Respuesta :
Answer:
Step-by-step explanation:
Substitution method can be applied in four steps.
Solve one of the equations for either x = or y = .
Substitute the solution from step 1 into the other equation.
Solve this new equation.
Solve for the second variable. ...
Step 1: Solve one of the equations for either x = or y =
Answer:
(8, - 1 )
Step-by-step explanation:
Given the 2 equations
x - y = 9 → (1)
x + y = 7 → (2)
Rearrange (1) expressing x in terms of y by adding y to both sides
x = 9 + y → (3)
Substitute x = 9 + y into (2)
9 + y + y = 7
9 + 2y = 7 ( subtract 9 from both sides )
2y = - 2 ( divide both sides by 2 )
y = - 1
Substitute y = - 1 into (3) for corresponding value of x
x = 9 - 1 = 8
Solution is (8, - 1 )