Solve each system of equations using substitution. Show all work.

1) x + y = 1

2x - y = - 2

2) 5x - 3y = - 11

x - 2y = 2

3) x - y = 3

6x + 4y = 13

It would be so much easier with elimination but ok

1.

x+y=1

minus x

y=1-x

sub

2x - (x-1) = - 2

2x-x+1=-2

x+1=-2

x=-3

sub

y=1-x

y=1 - (-3)

y=1+3

y=4

(-3,4)

2.

x-2y=2

add 2y

x=2y+2

sub

5 (2y+2) - 3y=-11

10y+10-3y=-11

7y+10=-11

7y=-21

y=-3

sub

x=2y+2

x=2 (-3) + 2

x=-6+2

x=-4

(-3,-4)

3.

x-y=3

add y

x=y+3

sub

6 (y+3) + 4y=13

6y+18+4y=13

10y+18=13

10y=-5

y=-1/2

sub

x=y+3

x=-1/2+3

x=5/2

(5/2,-1/2)

1. (-3,4)

2. (-3,-4)

3. (5/2,-1/2)