If y varies directly s the square root of (x + 1) and y =...
If y varies directly s the square root of (x + 1) and y = 6 when x = 3, find x when y = 9
8
7
6
5
Correct answer is A
y α \sqrt{x + 1}\), y = k\sqrt{x + 1}\)
6 = k√3+1
6 = k√4
6 = 2k
k = 62 = 3
y = √(x+1)
9 = 3√(x+1)(divide both side by 3)
93 = 3√x+13
3 = √x+1(square both sides)
9 = x + 1
x = 9 - 1
x = 8