Answer:
Step-by-step explanation:
2x + 9 = 15
you move + 9 to the other side of the equation, you will get:
2x = 15 - 9
2x = 6
So, x = 3
Divide both by a number that can go into both terms so it will be 5 .
which is 5(c-3)
Your answer is:
(125 - 8x^3) / (25 + 10x + 4x^2) = - ((2x - 5) * (4x^2 + 10x + 25)) / (4x^2 + 10x + 25) = - (2x - 5) = - 2x + 5
The correct result would be - 2x + 5.
Let's first break it down to the time 8 people need for one wall. That would be 10 minutes, right? If one person would have to do it in stead of 8, you'd expect him to take 80 minutes.
To paint 7 walls, he would nee 7x80 = 560 minutes. 10 people would do that 10 times faster, ie., 56 minutes.
I know puzzles like these always have a mindtrick. Did I miss anything?? ;-)