All you have to do is subtract 10 from 3, which equals -7, and there you have an integer
Two cheaper books = x
more expensive = 1.5x
so, 2.5x=150
150/2.5=x=60
therefore the more expensive book = 90
4 = 2 * 2
Multiplying by 2 is the same a doubling.
Since 4 is 2 * 2, to multiply a number by 4, double the number twice.
Example:
What is 4 * 100?
Double 100 to get 200.
Double 200 to get 400.
Therefore, 4 * 100 = 400.
By doubling twice, we do the same as multiplying by 4.
I would say c. I’m not sure if I’m right if I’m not sorry but good luck
