Question

What is the solution to this system of linear equations? x + y = 4 x - y = 6

Answer 1

Answer: x = 5 , y = -1

Step-by-step explanation:

Given:

x + y = 4 ................. equation 1

x - y = 6 .................. equation 2

Solving the simultaneous equation by elimination method;

From equation 1 make x the subject of the formula , that is

x = 4 -y ............ equation 3

substitute equation 3 into equation 2 , we have

4 - y - y = 6

4 - 2y = 6

Add 2y to both sides , we have

4 = 6 + 2y

subtract 6 from both sides , we have

4 - 6 = 2y

- 2 = 2y

divide both sides by 2

-2/2 = y

Therefore : y = -1

Substitute y = -1 into equation 3 , we have

x = 4 - (-1)

x = 4 + 1

x = 5