The exact form is 17/10, decimal form is 1.7, and mixed number form is 1 7/10
X(7-x)>8 perform indicated multiplication on left side
7x-x^2>8 divide both sides by -1
x^2-7x<-8 halve the linear coefficient, square it, and add it to both side ie (-7/2)^2=12.25
x^2-7x+12.25<4.25 now the left side is a perfect square
(x-3.5)^2<4.25 take the square root of both sides
x-3.5<±√4.25 add 3.5 to both sides
x<3.5±√4.25
So x>3.5-√4.25 and x<3.5+√4.25 or if you want approximations
x>1.44 and x<5.56 or in interval notation:
x=(1.44, 5.56) (to nearest hundredths)
We must first open the parenthesis. We get 15*7+15y, or 105+15y. We can now add 12 to 105 which would be 117. Now we have -4-5y+117+15y. With this we can move the -4 to 117 which is 113 and the -5y to 15y which is 10y. So we got 113+10y as our answer.
Hope this helps. <3