Let us solve the following simultaneous equations in two variables by the method of comparison:
2 – 2(3x – y) = 10

10(4 – y) – 5x = 4(y – x)

Question

Let us solve the following simultaneous equations in two variables by the method of comparison:2 – 2(3x – y) = 1010(4 – y) – 5x = 4(y – x)

Philoid · Accepted Answer

expressing the equations in terms of one variable

2 – 2(3x – y) = 10

⇒ 2 – 6x + 2y = 10

⇒ 6x = 2y – 8

dividing by 3 on both sides.

⇒ 3x = y – 4

………[1]

10(4 – y) – 5x = 4(y – x)

⇒ 40 – 10y – 5x = 4y – 4x

⇒ x + 14y = 40

⇒ x = 40 – 14y ………[2]

by comparing eq. [1] and eq. [2]

⇒ y – 4 = 120 – 42y

………[3]

by using [3] in [1]