Answer:
54.2 mph
Step-by-step explanation:
Since the drivers leave at the same time and travel in directions 90° from each other, their separation speed can be found using the Pythagorean theorem. Let c represent Cynthia's average speed. Then (c-10) will represent Tim's average speed. Their combined separation speed is 70 miles per hour, so we can write ...
70² = c² +(c -10)²
4900 = 2c² -20c +100 . . . . eliminate parentheses
c² -10c -2400 = 0 . . . . . . . . divide by 2; put in standard form
(c -5)² -2425 = 0 . . . . . . . . . rearrange to vertex form
c = 5 ±5√97 . . . . . . . . . . . . solve for c, simplify radical
c ≈ 54.244 ≈ 54.2 . . . . . . . use the positive solution
Cynthia's average speed was 54.2 miles per hour.
I = PRT
720 = (1,000)(0.09)(t)
720 = 90(t)
720/90 = t
8 = t or t = 8
I am not sure if it is terms of months or years but 8 is the answer. hope it helps :)
Hello there! x = 66.
x/6 + 4 = 15
This means that since 15 - 4 = 11, x/6 = 11.
Given the two numbers and a variable, we can multiply:
6 x 11 = 66
66/6 = 11
Therefore, x = 66
Hope this helps!
