I believe the equation is y=350+150x with y being the total amount of money in his account and x being the number of months..Paul starts with $350, which is the y-intercept (starting value) of the equation then the slope is 150 because his total savings increases by $150 for every month he saves without making any withdrawals. I apologize if I'm wrong but I hope this helps.
A) 2x-7=13
2x=20
x=10
B) 3x+4=25
3x=21
x=7
32-x=0; with x equaling the amount descended or -32.
