If x - 3 is directly proportional to the square... - JAMB Mathematics 2008 Question
If x - 3 is directly proportional to the square of y and x = 5 when y = 2, find x when y = 6
A
30
B
21
C
16
D
12
correct option: b
x - 3 x y2
x - 3 = ky2
when x = 5, y = 2
5 - 3 = k(2)2
2 = 4k
k = \(\frac{2}{4}\)
k = \(\frac{1}{2}\)
Find x when y = 6
from x - 3 = ky2
x - 3 = \(\frac{1}{2}\)ky2
x - 3 = \(\frac{1}{2}\) x 36
x - 3 = 18
x = 18 + 3
x = 21
x - 3 = ky2
when x = 5, y = 2
5 - 3 = k(2)2
2 = 4k
k = \(\frac{2}{4}\)
k = \(\frac{1}{2}\)
Find x when y = 6
from x - 3 = ky2
x - 3 = \(\frac{1}{2}\)ky2
x - 3 = \(\frac{1}{2}\) x 36
x - 3 = 18
x = 18 + 3
x = 21
Please share this, thanks:
Add your answer
No responses