Question

P(a, b) terletak pada garis lurus yang melalui (-2,4) dan (3,-6). jika nilai b =16, nilai a ??

Answer 1

Persamaan garis :

y - y1 = x - x1
y2-y1    x2-x1

y - 4 = x - (-2)
-6 -4    3-(-2)

y - 4 = x + 2
 -10       5

5y - 20 = -10x - 20
5y = -10x - 20 + 20
5y = -10x
y = -2x

b = y = 16

16 = -2x
-2x = 16
2x = -16
x = -16 / 2
x = -8

x = a
a = -8

Answer 2

(-2,4) ; (3,-6) ; (a,16)

-6-4 = 16+6
3+2      a-3

-10 = 22
5      a-3

-10a + 30 = 110
-10a = 110-30
-10a = 80
a = 80/-10
a = -8