4a²b⁴ - 25x⁶y⁴
(2ab²)² - (5x³y²)²
= (2ab² + 5x³y²)(<span>2ab² - 5x³y²) By difference of two squares</span>
If x =-5 then you put -5 in place of x.
y=-5+7
y=2
Let x be the number of days.
If Ashley posts 17 status updates each day, then after x days Ashley posts 17x status updates.
If Roberto posts 21 status updates each day, then after x days Roberto posts 21x status updates.
Part A. The combined number of posts for Ashley and Roberto after x days is:
17x+21x.
Part B. The difference between number of posts for Ashley and Roberto after x days is:
21x-17x.
1). 2x-1>0
2x>1
x>½
2) 21-3y<0
-3y<-21
y>7
3) 5-3c>80
-3c>75
c<-25