Question

Solve for y by using elimination
-4x + 8y = 10

7x + 9y = 19

Answer 1

-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)

Answer 2

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