The solution to the system of equations are (2, 5).
Solution:
The system of equations are
x + y = 7 – – – – (1)
2x – y = –1 – – – – (2)
To find x from equation (1):
x + y = 7
Subtract y from both sides of the equation, we get
⇒ x + y – y = 7 – y
⇒ x = 7 – y – – – (3)
Substitute (3) in (2) we get,
2(7 – y) – y = –1
14 – 2y – y = –1
14 – 3y = –1
Subtract 14 from both sides,
–3y = –15
Divide by –5 on both sides,
y = 5
Substitute y = 5 in equation (3)
x = 7 – 5
x = 2
The solution to the system of equations are (2, 5).