$5.25, because if you multiply $6 by 7/8(fraction form), you get $5.25
Using the equation y=9x you can substitute x for the hours. Y=9 times 5 and y=9 times 8. Y=45 and y=72. The range is $45-$72
we will find the area of triangle with sides 5y,6y and 9y using herons formula
12a=x
4a+6b=10
2a+3b=5
2a-4b=12
a-2b=6
2a+3b+1=a-2b
a+5b+1=0
a=-1-5b
2(-1-5b)+3b=5
-2-10b+3b=5
-2-7b=5
-7b=7
7b=-7
b=-1
-1-5*-1=a
-1+5=a
4=a
4*12=48
12a=48
Hope this helps :)