Question

What is the solution to the following system of equations?

y = x2 + 10x + 11
y = x2 + x − 7

Answer 1

It should be (-2,-5)

Explanation:

We could easily check the answer by subbing in x and y with the answer

y=x^2+10x+11

-5=-2^2+10(-2)+11

-5=4-20+11

-5=5

y=x2+x-7

-5=(-2)^2+-2-7

-5=-5

Therefore it should be A, (-2,-5)

Answer 2

Equation 1) y = x² + 10x + 11
Equation 2) y = x² + x - 7

Subtract equations from one another.

9x = 18

Divide both sides by 9.

x = 2

Plug in 2 for x in the first equation.

y = x² + 10x + 11

y = 2² + 10(2) + 11

Simplify.

y = 4 + 20 + 11

y = 35

Plug in 35 for y and 2 for x in the first equation to check your work.

y = x² + 10x + 11

35 = 2² + 10(2) + 11

35 = 4 + 20 + 11

35 = 24 + 11

35 = 35

So, we know that our answer is correct! :))

x = 2, y = 35