Question

I need help solving each equation by the substitution method.
1. X=5y-1
X+2y=13

2. -2x+3y=11
X=4y-3

3. X=-9y-1
2x+4y=5

I need help on these so please guide me in the right direction because I'm struggling on this topic!!

Answer 1

1)
use 5 y - 1 for x
so
5 y-1 + 2y = 13
or
7 y - 1 = 13
7 y = 14
y = 2
now go back and get x
x = 5(2)-1
x = 9

Answer 2

2)
-2x+3y=11
X=4y-3

-2 (4y-3) + 3 y = 11

-8 y + 6 + 3 y = 11
- 5 y + 6 = 11
-5y = 5
y=-1
etc