4) a. x+y=1–(1)
y=2x-8—(2)
(2) into (1)
x+(2x-8)=1
3x-8=1
3x=1+8
x=9/3
x=3—(3)
(3) into (2)
y=2(3)-8
y=-2
ans x=3, y=-2
b. x+y=19—(1)
y=5x+1—(2)
(2) into (1)
x+(5x+1)=19
6x+1=19
6x=19-1
x=18/6
x=3—(3)
(3) into (2)
y=5(3)+1
y=16
ans x=3, y=16
c.x+y=-2—(1)
y=x-10—(2)
(2) into (1)
x+(x-10)=-2
2x-10=-2
2x=-2+10
x=8/2
x=4–(3)
(3) into (2)
y=4-10
y=-6
ans x=4, y=-6
5) 3x=y—(1)
x=y-16–(2)
(2) into (1)
3(y-16)=y
3y-48=y
2y=48
y=48/2
y=24–(3)
(3) into (2)
x=24-16
x=8
ans x=8, y=24
9 times 5 is 45
6 times 5 is 30
Difference is 15
