D) because the first equation*3-the second equation*;
the left side=0, the right side = 36
Answer:
30 mph
Step-by-step explanation:
time = distance/speed
If x represents Jane's speed along the summit then her total exploration time is ...
12/x + 40/(x -5) = 2 . . . . . hours
Multiplying by (x)(x -5), we get ...
12(x -5) +40(x) = 2(x)(x -5)
Dividing by 2 and subtracting the left side gives ...
x^2 -31x +30 = 0
(x -30)(x -1) = 0 . . . . . factor
Solutions are x = 30 and x = 1, values of x that make the factors zero. A speed of 1 mph makes no sense in this problem, so ...
Jane's speed along the summit was 30 mph.
The given sequence;–3.2, 4.8, –7.2, 10.8, is a geometric progression common ratio of -1.5.
<h3>What is a geometric series?</h3>
When all the terms of a geometric sequence are added, then that expression is called geometric series.
The given sequence ;
–3.2, 4.8, –7.2, 10.8, …
The common ratio
= -4.8/ 3.2
= - 1.5
The terms having a common ratio of -1.5 best describe the relationship between the successive terms in the sequence of the terms.
Learn more about geometric sequence here:
brainly.com/question/2735005
#SPJ1