Hello! So the formula for compound interest is P(1 + r)^t, where r = rate, P = principal, and t = time (years). C is out, because you multiply the rate and principal together to get the price, not add. You raise the decimal to a certain power, based on the amount of years. You add 1 to the rate. 5% in decimal form is 0.05 and you must add 1 to the amount, which eliminated B. The only answer that works is A, because it shows the correct formula. The answer is A.
2*10^8
the exponent would be 8
hope this helps!
The answer is D. 63. You have to set up a proportion as shwon in the image.
If their perimeters are equal, we can add up all the side lengths of each triangle, and set the perimeters equal to each other to find the value of x that satisfies the equation:
x - 2 + x + 3x + 1 = 2x - 5 + x + 4 + 6x - 7
Combine like terms:
5x - 1 = 9x - 8
And finally, solve for x:
7 = 4x
x = 
Therefore, x is equal to
.
<em>Hope this helps! :)</em>