Answer:
(5x - 7) + 9x
Step-by-step explanation:
Let's call the number , and let's write down all the components of this problem:
"The square of a number"
"three times the sum of the number and 7"
"the product of that number and 15"
Now, we want the difference between the first two:
And this must be greather than, , the third one. So, we finally have
(5x+1)+(5x+2)=28
(because ab+bc=ac)
10x+3=28
10x=25
x=2.5
then plug 2.5 into ab equation:
5(2.5)+1=ab
ab=13.5