Recall d = rt, distance = rate * time.
now, he has a speed rate of 56 mph for a distance of 504

so, at that speed the whole driving time is 9 hours then. Ok, he drove 2 hours today, that means he drove 7 yesterday, 9 - 2.
how many miles is it for 7 hours at 56mph? d = rt ---> d = 56 * 7
that many miles he drove yesterday.
Answer:
x = 5/4
y = 7/4
Step-by-step explanation:
The smaller triangle and the larger one are similar, so the sides are proportional.
(x+5)/5 = 10/8
x/5 + 1 = 1/4 + 1 . . . . . divide it out
x/5 = 1/4 . . . . . . . . . . .subtract 1
x = 5/4 . . . . . . . . . . . . multiply by 5
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For y, you can do exactly the same computations, replacing every instance of 5 with a 7. Then you get ...
y = 7/4
Answer:-30
Step-by-step explanation:kinda hard to tell a little shaky so sorry if it is wrong.
Answer:
Step-by-step explanation:
For a first order decay, fraction remaining = 0.5n where n = number of half lives elapsed.
fraction remaining = 55% = 0.55
0.55 = 0.5n
log 0.55 = n log 0.5
-0.2596 = -0.301 n
n = 0.8625 = # of half lives elapsed
0.8625 half lives x 2.5 billion years/half live = 2.16 billion years have elapsed = age of the rock
b) 0.15 = 0.5n
log 0.15 = n log 0.5
-0.824 = -0.301 n
n = 2.74 half lives
2.5 billion years/half life x 2.74 half lives = 6.85 billion years = age of rock