Solve the following equations by substitution method.

2x + y = 1; 3x – 4y = 18

[In substitution method, we have to find value of one variable in terms of the other variable from any one of the two given equations . Then, we will substitute this value in the other equation. By doing this, we will get a equation in one variable which can be solved easily]

2x + y = 1….(1)

3x – 4y = 18….(2)

From eq(1),

2x + y = 1….(1)

⇒ y = 1 – 2x

Substituting the value of y in eq(2)

3x – 4y = 18….(2)

⇒ 3x – 4(1 – 2x) = 18

⇒ 3x – 4 + 8x = 18

⇒ 11x + 4 = 18

⇒ 11x = 18 + 4

⇒ 11x = 22

⟹x =

⇒ x = 2

Substituting the value of x in eq(1),

⇒ 2x + y = 1

⇒ 2×2 + y = 1

⇒ y = 1 – 4

⇒ y = – 3

Hence,

x = 2,y = – 3