Answer:
False
Step-by-step explanation:
t=D/r
Divide r by both sides to get t by itself.
You set up a proportion. first, put the percent so if it's 30 percent, it would be 30 over 100. Then, set up the second part. is over of.
-4x^2 - 8......input (x) = 2
-4(2^2) - 8 =
-4(4) - 8 =
-16 - 8 =
- 24 <==
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.
