Question

Find the solution to the system of equations x + y = 9 and x - y = -1.

Answer 1

Answer: x = 4, y = 5

Explanation:

=> x + y = 9 (Eq. 1)
=> x - y = -1 (Eq. 2)

Lets Solve by Elimination Method.

Adding Eq. 1 and Eq. 2, we get :-

2x = 9 - 1
2x = 8
x = 8/2
=> x = 4

Therefore, x = 4

Substitute value of ‘x’ in Eq. 1 :-

x + y = 9
4 + y = 9
y = 9 - 4
=> y = 5

Therefore, y = 5

Hence, x = 4 and y = 5 (4, 5)

Answer 2

(4, 5 )

Explanation:

x + y = 9 → (1)

x - y = - 1 → (2)

adding the 2 equations term by term will eliminate y

2x + 0 = 8

2x = 8 ( divide both sides by 2 )

x = 4

substitute x = 4 into either of the 2 equations and solve for y

substituting into (1)

4 + y = 9 ( subtract 4 from both sides )

y = 5

solution is (4, 5 )