SOLUTION: Hello, I need help with this: If y varies directly as x and y = 25 when x = 10, find y when x = 4. Thank you

Question 91816: Hello,

I need help with this:

If y varies directly as x and y = 25 when x = 10, find y when x = 4.

Thank you
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
If y varies directly as x, you can write this as:
y = kx where k is called the constant of proportionality.
To find the value of k, substitute the given values of y (25) and x (10) and solve for k.
25 = 10k Divide both sides by 10.
k = 2.5
Now you have: y = 2.5x so you can find the value of y when x = 4.
y = 2.5(4)
y = 10
RELATED QUESTIONS
please help.. they are indirect and direct variations, please show work.. asap 3.If y... (answered by RAY100)

I need help solving. Thank you. If z varies directly as x and inversely as y, and z =... (answered by Fombitz)

This has to do with direct, indirect, and joint variation. Sorry but I couldn't find it... (answered by Mathtut)

I need help solving this problem. If y varies directly as x and y = 14 when x = 7,... (answered by littlebitlove)

1. If y varies inversely as x, and y=11 when x=8, find y when x=10 Please help me with... (answered by Tatiana_Stebko)

Could I please have some help solving this problem. Thank you. x varies directly with y... (answered by stanbon)

If y varies directly as x, and x = 10 when y = 4, find y when x =... (answered by math_helper)

If y varies directly as x and x=10 when y=4, find y when... (answered by ewatrrr)

y varies inversely as x^2. If y=25 when x=2, then find y when y=10. thank... (answered by josgarithmetic)