Question

4) Solve each pair of simultaneous equations.

a. x+y=1 y=2x-8
b. x+y= 19 y=5x+1
c. x+y=-2 y=x-10



5) Solve these simultaneous equations.
3x=y x=y-16​

Answer 1

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