Question

Pi High school ordered 40 science books. The next week, the school ordered 30 algebra books. The bill for the first order was $360 greater than the bill for the second order. The two bills together total $3960. Find the price of an algebra book?

Answer 1

40s=360+30a
40s+30a=$3960

40s=360+30a
40s/40=360+30a/40
s = 9+3/4a

40(9+3/4a) +30a=$3960
360+30a+30a=$3960
360+60a=$3960
360-360+60a=$3960
60a=$3960
60a/60 = $3960/60
a= $60
The algebra book is $60