If y varies directly s the square root of x 1 a... - WAEC Mathematics 2013 Question

y (\alpha) \sqrt{x + 1}), y = k\sqrt{x + 1})

6 = k(\sqrt{3 + 1})

6 = k(\sqrt{4})

6 = 2k

k = (\frac{6}{2}) = 3

y = (\sqrt{(x + 1)})

9 = 3(\sqrt{(x + 1)})(divide both side by 3)

(\frac{9}{3}) = (\frac{3\sqrt{x + 1}}{3})

3 = (\sqrt{x + 1})(square both sides)

9 = x + 1

x = 9 - 1

x = 8