mmmh, they gave you the equation
y = kx^2
when y = 50, x = 10 , so....
50 = k(100)
k = 1/2
your equation is y = (1/2)x^2
now just plug in x = 30
in your head you can do y = 900/2 or 450
when y varies directly at the square of X, the variation equation is written y= kx square, where K is constitution
(a) given that y=50 when x=10,find the value of K.
(b) calculate the value of y when X= 30
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