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

Answer :

Answer:

y = 125

Step-by-step explanation:

Given that,

y is directly proportional to x² i.e.

[tex]y=kx^2[/tex]

k is a constant of proportionality

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

[tex]k=\dfrac{y}{x^2}\\\\k=\dfrac{20}{(2)^2}\\\\k=5[/tex]

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

[tex]y=5\times (5)^2\\\\y=125[/tex]

So, the value of y is equal to 125.