sam makes $400 per week plus $20 commission oh each new cell phone plan she sells. write an equation to determine how many new plans she sold to earn $680 last week.
To write the equation, you can start with the answer of $680. She receives $400 + $20*plans sold:
400 + 20p = 680
20p = 280
p = 14
{$400 + $20 * 14 = 680}
Sam sold 14 plans to make a total of $680.
