Question

To solve the system of equations below, Grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation?

Answer 1

A

Explanation:

given the 2 equations

4y = 8x → (1)

`(x^2)/(25)` -
`(y^2)/(49)` = 1

in (1) divide both sides by 4

`(4)/(4)` y =
`(8)/(4)` x

y = 2x

substitute y = 2x into (2)

noting that (2x)² = 2x × 2x = 4x²

`(x^2)/(25)` -
`((2x)^2)/(49)` = 1 , that is

`(x^2)/(25)` -
`(4x^2)/(49)` = 1