<PRE><B>Question 347998</B>
2X*5+X*10=680

Multiply 2X by 5 to get 10X.
10X+X*10=680

Multiply X by 10 to get 10X.
10X+10X=680

Since 10X and 10X are like terms, add 10X to 10X to get 20X.
20X=680

Divide each term in the equation by 20.
(20X)/(20)=(680)/(20)

Simplify the left-hand side of the equation by canceling the common factors.
X=(680)/(20)

Simplify the right-hand side of the equation by simplifying each term.
X=34 tens
  68 fives


Prove:

34*10= 340
68*5= 340
340+340=680</PRE>