Question

suppose y varies directly with x, and y =25 when x = 140. What is the value of x when y = 36?

Answer 1

"something" varies directly to "something else" means

"something" = "some value" * "something else"
y = "some value" * x
y = n x

what's "some value"? we dunno

but we know that when x = 140, y = 25

so let's use that in the equation \(\bf y = (n)x\implies 25=n140\implies \cfrac{25}{140}=n\)

now that we know what "n" is, we want to know what "x" is when y = 36
so \(\bf y = (n)x\implies 36=(n)x\)

Answer 2

and just solve for "x"

Answer 3

25=140 x 36=
25=5040 divide each side by 25
x=201.6 ??

Answer 4

yes