The value of y is directly proportional to the value of x. If y=8 when x=10, what is the value of y when x=25?

30

Step-by-step explanation:the initial statement is

y ∝ x

to convert to an equation multiply by k the constant

of variation

⇒ y = k x

to find k use the given condition

y = − 24 when x = 8 y = k x ⇒ k = y x = −22

∣

∣

∣22 y = − 3 x 22

∣∣∣

−−−−−−−−−−−−−−

when  x = 10

then y = − 3 × 10 = −30

19

step-by-step explanation: