SIMULTANEOUS LINEAR EQUATIONS ( SUBSTITUTION METHOD)

Solve the following simultaneous linear equatioans

x = 6 - y

3x = 20 - 4y

Solution : SUBSTITUTION METHOD

x = 6 - y                  -------------(1)

3x = 20 - 4y            -------------(2)

Substitute (1) into (2)

3(6 - y) = 20 - 4y

18 - 3y = 20 - 4y

-3y + 4y = 20 - 18

y = 2

From (1) subtitute y = 2

x = 6 - 2

x = 4