Question

x - 3y = 8, 5x + 3y = 10 solve by substitution method.

Answer 1

x - 3y = 8

⇒ x = 8 + 3y

∴ 5(8 + 3y) + 3y = 10

⇒ 40 + 18y = 10

⇒ 18y = -30

⇒ \(y = \frac{-30}{18} = \frac{-5}3\)

∴ x = 8 + 3y 

= \(8 + 3\left(\frac{-5}3\right)\)

= 8 - 5

= 3