Is the percent increase from 50 to 70 equal to the percent
decrease from 70 to 50? Explain.

No.

Summary reason:

While the positive difference is the same, the original number is not. You are comparing the following ratios 20/50 and 20/70 respectively. As we can see, these are different numbers so they represent different percentages.

Step-by-step explanation:

The question is asking is the the positive difference over the original the same in each one. While the positive difference is 20 in both, the original is different. This makes the percent changes different as 20/50 does not equal 20/70.

That is, I'm just doing

(Biggest-Smallest)/original .

So the first one we have increase of

(70-50)/50=20/50=2/5=.4=40%

So the second one we have a decrease of

(70-50)/70=20/70=2/7=approximately 28.6%.

As you can clearly see these percentages are not equal.

yes

step-by-step explanation:

yes

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x