This is a difference of perfect squares which is of the form:
(a^2-b^2)
And which always factors to:
(a-b)(a+b)
In this case:
(5x-8)(5x+8)
Answer: -8
Here’s why: you start by subtracting the 4 from both sides. Leaving you with
-7y= 56
Divide by -7 on both sides
-7y/-7 = y 56/-7=-8
A can do 1 job in 10 min. means 1/10 job per min.
B can do 1/15 job per min.
together A&B can do 1/10+1/15 =1/6 job per min.
1/6 job they spend 1 min
1 spend 1x1/(1/6) = 6 min
5.3 to be exact but does it say you round up in the problem? Cause then I’d put 5.5 cups or 6