Question

Solve the simultaneous equations
5x + y = 21
3x + y = 13
X =
Y =

Answer 1

x=? y=?

• 5x+y=21 equation 1
• 3x+y=13

y=13-3x

• y=13-3x in equation 1

5x+(13-3x)=21

5x+13-3x=21

2x+13=21

2x=21-13

2x=8

x=8/2

x=4

• x=4 in equation 1
• 5(4)+y=21

20+y=21

y=21-20

y=1