Problem of the Week

Updated at Mar 8, 2021 3:19 PM

To get more practice in equation, we brought you this problem of the week:

How would you solve the equation $$(\frac{u}{5}-5)\times \frac{5}{3-u}=21$$?

Check out the solution below!

$(\frac{u}{5}-5)\times \frac{5}{3-u}=21$

 1 Expand.$\frac{u}{3-u}-\frac{25}{3-u}=21$2 Join the denominators.$\frac{u-25}{3-u}=21$3 Multiply both sides by $$3-u$$.$u-25=21(3-u)$4 Expand.$u-25=63-21u$5 Add $$25$$ to both sides.$u=63-21u+25$6 Simplify  $$63-21u+25$$  to  $$-21u+88$$.$u=-21u+88$7 Add $$21u$$ to both sides.$u+21u=88$8 Simplify  $$u+21u$$  to  $$22u$$.$22u=88$9 Divide both sides by $$22$$.$u=\frac{88}{22}$10 Simplify  $$\frac{88}{22}$$  to  $$4$$.$u=4$Doneu=4