Question

Use substitution to solve each system of equations.

x – 5y = –3
–7x + 8y = –33

A(2, 7)

B(–5, 1)

C(7, 2)

D(1, –5)

Answer 1

I think it’s C sorry if I’m wrong

Answer 2

For this case we have a system of sos equations with two unknowns:

`x-5y = -3\\-7x + 8y = -33`

We clear "x" from the first equation:

`x = -3 + 5y`

We substitute in the second equation:

`-7 (-3 + 5y) + 8y = -33\\21-35y + 8y = -33\\-27y = -33-21\\-27y = -54\\y = \frac {-54} {- 27}\\y = 2`

We find the value of "x":

`x = -3 + 5 (2)\\x = -3 + 10\\x = 7`

ANswer:

(7,2)

Option C