Question

Agar sistem persamaan
2x - y -1 =0
4x - y - 5 =0
ax - y - 7 =0

mempunyai penyelesaian, maka nilai a adalah ?
tolong jawab kk

Answer 1

2x - y - 1 = 0
2x - y = 1

4x - y - 5 = 0
4x - y = 5

4x - y = 5
2x - y = 1_ -
2x = 4
x = 4/2
x = 2

2x - y = 1
2(2) - y = 1
4 - y = 1
-y = 1 - 4
-y = -3
y = 3

ax - y - 7 = 0
a(2) - 3 - 7 = 0
2a - 10 = 0
2a = 10
a = 10/2
a = 5