Question

Y is directly proportional to x squared if y=20 when x=2 find y when x= 5

Answer 1

Answer:

y = 125

Step-by-step explanation:

Given that,

y is directly proportional to x² i.e.

$y=kx^2$

k is a constant of proportionality

Put y = 20 and x = 2 in the given equation to find k.

$k=\dfrac{y}{x^2}\\\\k=\dfrac{20}{(2)^2}\\\\k=5$

Now put k = 5 and x = 5 in the given equation to find y.

$y=5\times (5)^2\\\\y=125$

So, the value of y is equal to 125.