Nickels is 0,05 of dolar - n
dimes is 0,1 o dolar -d
quarters is 0,25 of dolar -q
dimes =2nickels
d=2n
quarters=2dimes
q=2d=4n
12,5=n(0,05)+2n(0,1)+4n(0,25)
12,5=0,05n+0,2n+n
12,5=1,25n
n=10
q=4n=40
There are 40 quarters
Hint: The word "please" often works wonders.
In this case, it's hard to believe that you actually can't do this one on your own.
4(-11) is the problem, and the instruction says "Find the product:".
That means: "Multiply 4 by -11 ."
All you have to do is multiply 4 by 11, get 44, and then remember that when the signs of two mumbers are different, their product is negative. So it's -44 .