Question

Garis ax +by = 11 dan 5x - 7y = b berpotongan di titik (2,1). nilai a+b =...

Answer 1

Ax + by = 11
5x - 7y = b

(2,1)
 (x,y)

2a + b = 11
10 - 7 = b
b = 3

subtitusi:
2a + b = 11
2a = 11 - 3
2a =8
a = 4

a + b = 4 + 3 = 7

Answer 2

Titik perpotongan = (2, 1), maka
b = 5(2) - 7(1) = 10 - 7 = 3

a(2) + (3)(1) = 11
2a + 3 = 11
2a = 8
a = 4
jadi a + b = 4 + 3 = 7