First, convert 3/5 to a percent by multiplying it by 20/20, getting 60/100, or 60%. Then, find 60% of 40 by multiplying 60 by 40 to get 2,400 and divide it by 100 to get 24, meaning Mark spend $24 on both books. Each of the books cost $12, as 24/2 is 12.
Step-by-step explanation:
So you add one over the other
3x-2y=7
-3x+5y=5
=
3y=12
Then you divide 3 from both sides
(3y)/3=12/3
y=4
Then you substitute the y=4 in to the equation of your choice
3x-2(4)=7
3x-8=7
3x-8=7
+8 +8
3x=15
x=5
I wrote out the steps on the attached slide. I hope I'm able to help you, Sweetie.
According to (P)arenthesis (E)xponets (M)ultiply (D)ivide (A)dd (S)ubtract, it would be (1 / 7).