Question

A) x+y=10. B) x+y=14
x-y=2. x-y=4

C) x+y=21. D) x+y=12
x-y=1. x-y=2

E) x+1=y. F) x-6=y
x+y=15. x+y=18

Answer 1

a
x=2+y

2+y+y=10
2y=10-2
y=4

x+4=10
x=10-4
x=6

b
x=4+y

4+y+y=14
2y=14-4
y=5

x-5=4
x=4+5
x=9

c
x=1+y

1+y+y=21
2y=21-1
y=10

x-10=1
x=1+10
x=11

d
x=2+y

2+y+y=12
2y=12-2
y=5

x-5=2
x=2+7
x=7