Penyelesaian sistem persamaan 3x – 2y = 7 dan 2x + 5y = 30 adalah (a,b + 1 ) hitunglah nilai 4a + b

3x – 2y = 7 |x2| 6x – 4y = 14
2x + 5y = 30 |x3| 6x + 15y = 90

6x – 4y = 14
6x + 15y = 90

-19y = -76
19y = 76
y = 76 / 19
y = 4

3x – 2y = 7
3x – 2(4) = 7
3x – 8 = 7
3x = 7+ 8
3x = 15
x = 5

( a, b+1 ) = (x,y)
x = a = 5
y = b+1 = -4
b = -4 – 1
b = -5

Nilai 4a + b = 4 (5) + (-5)
= 20 – 5
= 15.

Jadi, Nilai 4a + b adalah 15.