Question

Verificați care dintre perechile (4,7), (3, 4),
(2, -7), (7,4) sunt soluții ale ecuației
4x - 2y = 20.​

Answer 1

• (4, 7)
4(4) - 2(7) = 20
16 - 14 = 20
2 = 20 (wrong)

• (3, 4)
4(3) - 2(4) = 20
12 - 8 = 20
4 = 20 (wrong)

• (2, -7)
4(2) - 2(-7) = 20
8 + 14 = 20
22 = 20 (wrong)

• (7, 4)
4(7) - 2(4) = 20
28 - 8 = 20
20 = 20 (correct)

the answer is (7, 4)