-1/2x+y=10 i have to do some stupid slope intercept form

Jamie went to home depot. she bought 25 bags of soil that cost $9 per bag. she bought 15 pots at $8 each, and she bought 23 bags of pebbles at $15 each. she used a coupon that gave her $5 off for every 100 dollars she spent. how much did jamie pay at the end?

What is the value of x in the following equation. -x ^3/2 = -27

Define multiplicative inverse. give an example of a number and its multiplicative inverse.