learnt this topic a while ago and somehow completely forgot could someone explain?

Answer:

  C.  x = 3, y = -6

Step-by-step explanation:

You can divide the second equation by 2. Then you have ...

  x +2y = -9

This gives you a couple of choices for solution. The x-coefficients match, so subtracting one equation from the other eliminates x:

  (x +2y) -(x -2y) = (-9) -(15)

 4y = -24   ⇒   y = -6

Adding the two equations eliminates y:

  (x -2y) +(x +2y) = (15) +(-9)

  2x = 6   ⇒   x = 3

The solution is (x, y) = (3, -6).

_____

Additional comment

I find it quick and easy to use a graphing calculator to find the solution. Many graphing calculators also make it simple to solve systems of equations in matrix form. Either way, you can obtain a solution in little more than the time it takes to enter the equations (or their coefficients).

Answer:

Step-by-step explanation:

Surface area = (Perimeter of the base × Length of the prism) + (2 × Base Area) = (S1 + S2+ S3)L + bh

S.A=(help me)

Step-by-step explanation:

so, we need to find the smallest common multiple of 36 and 42.

that is the smallest number I can divide both by 36 and 42 without remain.

let's use the method of basic prime factors (we start with the smallest fitting prime number - 2 is a prime number too - and divide as often as possible, then continue with the next bigger prime number, until there is nothing left to divide) :

36 / 2 = 18

18 / 2 = 9

9 / 3 = 3

3 / 3 = 1 finished

therefore,

36 = 2×2×3×3

42 / 2 = 21

21 / 3 = 7

7 / 5 does not work

7 / 7 = 1 finished

therefore,

42 = 2×3×7

to find the smallest common multiple (SCM) we check the maximum length of each prime factor sequence.

and we see 2 times 2, 2 times 3 and 1 time 7.

so, the SCM = 2×2×3×3×7 = 252.

there is no smaller number that can be divided by both 36 and 42 without remain.

so, the rod must be at least 252 cm long to cut it into equally long pieces of either 36 cm (7 pieces) or 42 cm (6 pieces).

Answer:

3 is the answer because it's value only add by the 3

Answer:

2.42

Step-by-step explanation:

I AM VERY SORRY IF ITS WRONG

Answer:

33.3%

Step-by-step explanation:

10/ 30= 0.3(3 would be a reoccurring decimal)

0.3*100=33.3

10% of students take the bus

Answer:

5

Step-by-step explanation:

It is the greatest exponent.

Answer:

x² + 8x + 15

Step-by-step explanation:

(x +3)(x+5)

=> x² + 5x + 3x + 15

=> x² + 8x + 15

So, after simplifying, we can conclude that x² + 8x + 15 is our answer. Hoped this helped.

Answer:

x = 5

Step-by-step explanation:

|2x + 6| = 16

=> 2x + 6 = 16

=> 2x = 16 - 6

=> 2x = 10

=> x = 5

Hoped this helped.

Answer:

A. [tex]h(x)=f(x+1)[/tex]

Step-by-step explanation:

Let's start doing exactly what each function says.

[tex]g(x) = 3x+3[/tex]

At this point, let's see what the various h-s do. Let's call each [tex]h_A... h_D[/tex] to understand which flavor of it we're talking about.

[tex]h_A(x)=f(x+1) = 3(x+1)=3x+3 = g(x)\\h_B(x)=2f(x)=2\cdot3x= 6x \ne g(x)\\h_C(x)=f(x-1)=3(x-1)=3x-3\ne g(x)\\h_D(x)= f(x)+1= 3x+1\ne g(x)[/tex]

Answer:

Answer:Back 2

Step-by-step explanation:Blue + Red=-2

Step-by-step explanation:

Answer:

C. 97.1 should be your answer

Step-by-step explanation:

Answer:

-10 OR 4

Step-by-step explanation:

Answer:

21.8

Step-by-step explanation:

1.9 + 9 = 10.9

10.9 x 2 = 21.8

Answer:

21.8

Step-by-step explanation:

2×1.9=3.8

2×9=18

total=21.8

Answer:

  D. (-3, 26)

Step-by-step explanation:

The ratios of x- and y-coefficients are different in the two equations, so there will be a single solution. (Different ratios mean the slopes are different. Lines with different slopes must intersect in exactly one point.)

We can rearrange the first equation to give an expression for y:

  y = 17 -3x

This can be substituted into the second equation to give ...

  x +2(17 -3x) = 49

  -5x +34 = 49 . . . . . . simplify

  -5x = 15 . . . . . . . subtract 34

  x = -3 . . . . . . divide by -5

Then the value of y is ...

  y = 17 -3(-3) = 26

The single solution is (x, y) = (-3, 26).

Answer:

None

Step-by-step explanation:

A rational number can never be changed into irrational

Answer:

The answer to your question is None

Step-by-step explanation:

A rational number can never be changed into irrational.

In mathematics, the irrational numbers are all the real numbers that are not rational numbers. That is, irrational numbers cannot be expressed as the ratio of two integers.

I hope this helps and have a wonderful day!

Answer:

The 1st

Domain is (1,-3)

The second

Domain is (R)

The 3rd

Domain = (R)

The 4th

Domain =(-1,+infinity )

Respectively

Answer:

70%

Step-by-step explanation:

50-15 =35

35/50 = 70/100

Answer:

3.29

Step-by-step explanation:

4.32+6.86=11.18

11.18-7.89=3.29

Step-by-step explanation:

When you get negative it is ok.

It means you have a discount here, not really increase but decrease in price.

Here you have:

It is called 60% mark down or 60% discount

Answer: If you are asking for percentage, 18/400 bulbs were defective. In other words, 4.5% of bulbs were defective. This also means that 95.5% of bulbs were not defective.

Would appreciate brainly <3

Answer:

1/5 and 9/4

Step-by-step explanation:

Reciprocal is basically the vertically flipped version of the original number. To find the reciprocal, rewrite the numbers in fractions and then swap the numerator and the denominator. So 5/1 becomes 1/5, 4/9 becomes 9/4.

A mathematical expression is made up of terms (constants and variables) separated by mathematical operators. A mathematical equation is used to equate two expressions. Equation modelling is the process of writing a mathematical verbal expression in the form of a mathematical expression for correct analysis, observations and results of the given problem. The reciprocal of a number [x] is given by [1/x].

We have the following numbers -

5 and 4/9

We can write -

x = 5

y = 4/9

So, the reciprocal of [x] would be [1/x]. Therefore, the reciprocal of 5 will be 1/5.

The reciprocal of [y] would be [1/y]. Therefore, the reciprocal of 4/9 will be 9/4.

Therefore -

To solve more questions on Equations, Equation Modelling and Expressions visit the link below -

brainly.com/question/14441381

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Answer:

[tex]x = \frac{4y}{5}[/tex]

Step-by-step explanation:

[tex]5x = 4y\\\rule{150}{0.5}\\\frac{5x=4y}{5}\\\\\boxed{x = \frac{4y}{5}}[/tex]

Hope this helps.

The equation of the parabola is:

(y - 6)² = -12(x +2)

Parabola is the locus of a point such that its distance from a fixed point (called the focus) and a given line (called the directrix) is always the same.

The equation of a parabola is given by:

(y - k)² = 4p(x - h)

Where (h, k) is the vertex, (h + p, k) is the focus

Given the vertex of a parabola is (-2,6), and its focus is (-5,6).

Hence, k = 6, h = -2;

h + p = -5

-2 + p = -5

p = -3

Hence the equation of the parabola is:

(y - 6)² = -12(x +2)

Find out more at: https://brainly.com/question/21685473

[tex]\\ \sf\longmapsto 9\dfrac{7}{11}-(5+1\dfrac{1}{2})[/tex]

[tex]\\ \sf\longmapsto4 \dfrac{7}{11}-1\dfrac{1}{2}[/tex]

[tex]\\ \sf\longmapsto 4\dfrac{14}{22}-1\dfrac{11}{22}[/tex]

[tex]\\ \sf\longmapsto 3\dfrac{3}{22}[/tex]

Answer:

-3 1/20

Step-by-step explanation:

-3 1/20 is the first answer