Solve for y by using elimination

-4x + 8y = 10

7x + 9y = 19

-4x + 8y = 10 ⇒ - 28x + 56y = 70

7x + 9y = 19 ⇒ - 28x - 36y = - 76

92y = 146

92 92

y = 1²⁷/₄₆

7x + 9 (1²⁷/₄₆) = 10

7x + 14¹³/₄₆ = 10

- 14¹³/₄₆ - 14¹³/₄₆

7x = - 4¹³/₄₆

7 7

x = ⁻¹⁹⁷/₂₂

(x, y) = (⁻¹⁹⁷/₃₂₂, 1²⁷/₄₆)

Ok you said elimination, I included substitution and elimination, always take the easiest one, I took (Y) (8y) because it was positive, on the other equation, you can do the same, by working with the (X) (7x) because the quantity is smaller!

10 = 4x-8y=

We take the (Y) =

-8 + 10y - 4x=

10 (-8) + 10y - 4x=

2 + 10y-4=

2 - 4 + 10y

= 2 + 10y

Y = 10 - 2

Y=8