Answer:
(18, 3 )
Explanation:
Given the 2 equations
x + y = 21 → (1)
2x = 33 + y → (2)
Rearrange (2) expressing y in terms of x by subtracting 33 from both sides
y = 2x - 33 → (3)
Substitute y = 2x - 33 into (1)
x + 2x - 33 = 21, that is
3x - 33 = 21 ( add 33 to both sides )
3x = 54 ( divide both sides by 3 )
x = 18
Substitute x = 18 into (3) for corresponding value of y
y = (2 × 18) - 33 = 36 - 33 = 3
Solution is (18, 3 )