Help please! Thanks!!

None of them

I think your teacher made a typo. See explanation below for details

Explanation:

With math problems like this one, it is often very tricky to find integer solutions. Luckily, we're given a list of choices. Let's plug them in one at a time and see what happens.

If y = 5, then

y^2 - 7x^2 = 11

5^2 - 7x^2 = 11

25 - 7x^2 = 11

-7x^2 = 11-25

-7x^2 = -14

x^2 = -14/(-7)

x^2 = 2

But x^2 = 2 does not have any integer solutions. The two solutions are irrational. So we can rule out choice F.

Repeat for y = 4 and you should find that x^2 = 5/7, which also does not have any integer solutions. Choice G can be ruled out.

Choices H through K are even worse. Not only are there no integer solutions, but there aren't any real number solutions either (there are complex or imaginary solutions though). Plugging in y = 3 leads to x^2 = -2/7 which has imaginary solutions due to applying the square root to a negative radicand. Similar situations happen with J and K as well.

In summary, none of these answer choices are valid. We need to have two integers x and y that satisfy the equation. I think your teacher made a typo somewhere.

answer: d. $20

step-by-step explanation:

just took the test

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18