Question

Bobby wants to go on a school trip that will cost him $250. He comes up with an equation that represents how much he needs to save each week as follows: 25w+30=250, where W is the number of week spent saving.
If he has 9 weeks to save will you have enough money to go on the trip? Explain.

Answer 1

Yes, Bobby will have enough money if he saves for 9 weeks. You can find this through either substituting w for 9 in the equation, or solving the equation itself. 

Substituting:

$25(9)+30$
Substitute w for 9. 

$225+30$
Simplify. 

$225+30=255$
Solve. 

255 is greater than 250, so yes, he will have enough money saved. 


Solving the equation:

$25w+30=250$
Original Equation

$25w=220$
Subtract 30 from both sides. 

$w=8.8$
Divide both sides by 25. 

The number of weeks he needs is 8.8. When rounding it up, you get 9.