Question

Himpunan penyelesaian dari persamaan 4x + 7y = 7 dan 2x + y = 14 adlah {(a,b)} . Nilai dari a + b =

Answer 1

4× + 7y = 7 |×1| 4× + 7y = 7
2× + y = 14 |×2| 4× + 2y = 28
_______________ -
5y = -21 y = -21/5
2× - 21/5 = 14
2× = 14 + 21/5
2× = 91/5
× = 91/10

{(a,b)} = {(91/10 , -21/5 )}
a+b = 91/10 - 21/5 = 49/10 = 4,9