Question

Solve for X and Y with substitution

1.
`y=5-x\\2x+2y=6`

2.
`-7x-2y=-13\\x-2y=11`

Answer 1

1. x = no solution

y = no solution

2. x= 3

y = -4

Explanation:

y = 5 - x

2x + 2y = 6

Divide the equation by 2.

x + y = 3

x + (5 - x) = 3

x + 5 -x = 3

x-x + 5 =3

5 =3 ⇒⇒⇒ This is not true. So, we can say that the simultaneous equation don't have a solution.

-7x - 2y = -13

x - 2y = 11

x = 11 + 2y

-7(11 + 2y) - 2y = -13

-77 - 14y - 2y = -13

-16y = 64

y = -4

x = 11 + 2(-4)

= 11 - 8 = 3