When Paolo tried to simplify 5 - 7 at Step 2, instead of keeping the sign of the answer, -2, he added it. He really should have written 3 - 2.
Answer:
Each cookbook cost $15.15.
Step-by-step explanation:
Since the statement indicates that four cookbooks and one novel cost $68.75, you can write the following equation:
4x+y=68.75, where:
x is the price of cookbooks
y is the price of novels
Also, given that the novel cost 7 dollars less than a cookbook, you can write the following equation:
x=y+7
Now, you can replace x=y+7 in the first equation:
4(y+7)+y=68.75
4y+28+y=68.75
5y=40.75
y=40.75/5
y=8.15
Now, you can replace the value of y in x=y+7:
x=8.15+7
x=15.15
According to this, the answer is that each cookbook cost $15.15.
