Question

Solve by substitution method. a) x + y = 8 and x - y = 4​

Answer 1

x = 6

y = 2

Explanation:

x + y = 8 ---> (1)

x - y = 4 ---> (2)

First, let us find the value of x.

For that, add both equations.

(1) + (2)

x + y + ( x - y ) = 8 + 4

Solve the brackets.

x + y + x - y = 8 + 4

2x = 12

Divide both sides by 2.

x = 6

Now let us find the value of y.

For that, let us use equation 1 and replace x with 6.

x + y = 8

6 + y = 8

Subtract 6 from both sides.

y = 8 - 6

y = 2