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.

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:


Substitute w for 9. 


Simplify. 


Solve. 

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

Solving the equation:


Original Equation


Subtract 30 from both sides. 


Divide both sides by 25. 

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