Question

If y varies directly as x and y=3 when x=10, find x when y=8? Can you please show me step by step solution for this problem?

Answer 1

Whenever you have a statement such like yours,
"If y varies directly as x "
you can form the equation
y = kx , where k is a constant

sub in the given: y=3 , x=10 to find k
3 = k(10)
k = 3/10

so your equation is y = (3/10)x

then when y = 8

8 = (3/10)x
80 = 3x
x = 80/3

btw, if it has said" y varies inversely as x" your equation would have been
y = k(1/x), but you would follow the same steps of subbing in the given data to find k

Answer 2

Thank you so much that helps a lot!

Answer 3

welcome