Question

arianna's mom deposits $80 in her lunch account. Lunch costs $2.50 per day. Write and solve an inequality to determine when there will be less than $20 in her account.

I'm not sure how to set this up. would i subtract $80 to add it back to $20 on the other side of the inequality sign?

Answer 1

Yes.

80 - 2.5x > 20

Answer 2

to find y-intercept set x = 0
= -10(0) + 5y = 40  since -10(0) = 0 
= 0 + 5y = 40 
=> 5y = 40 divide both sides by 5 to get the value of Y 
=> y = 40/5 = 8 
=> the y-intercept for the above equation is 8 
to find x-intercept set y=0
= -10x + 5(0) = 40 since 5(0) = 0
= -10x = 40 divide both sides by -10 to find X
=> x = 40/-10 = -4
=> the x-intercept for the above equation is -4