Hello there!
1. Okay. So 70% is positive, so it is a corresponding growth. 70% is 0.7 in decimal form. C and D are both eliminated, because that's too large. When something grows by 70%, that is less than double. 0.7 is not right either, because that's more of a decay than a growth. The only answer that makes sense id 1.70, because you are going up, and adding 1 to decimal form brings you to the decimal that when multiplied will bring you to the total. The answer is B: 1.70.
2. So, -75% is negative, so it is a decay factor. A is eliminated, because it makes no sense and B is out, because that represents growth, not decay. You lose 75% of the amount overtime compounded, but you still have 25% that remains. To find that amount, you would subtract that amount from 1 to get the decay. 1 - 0.75 is 0.25. The decay factor is 0.25. The answer is D: 0.25.
Question 1:
4x+28
question 2:
18x-27
Ok so you round 31 to 30 and 43 to 40 and then you multiply 30 by 40 and get 1200. 1200 is the same thing as 1200.00 bc you can take off the zeros after the decimal and it will be the same. Hope this helped and if your still confused you let me know I'll try to explain it more.
1:3, Because you can simplify the numbers by dividing by two.