Hello :
P(x) + P(x') =1 ...( x' is the <span>complement of x)
0.3 +</span> P(x') =1
P(x') = 1 - 0.3 = 0.7
-7 - 8 - (-8) - 7 × 0(14) - 14 - 30
(I think that's what that says)
Do PEMDAS
0(14) = 0
-7 × 0 = 0
You're left with -7 - 8 - (-8) - 14 - 30
Go from left to right
-7 - 8 = -15
-15 - (-8) = -7
-7 - 14 = -21
-21 - 30 = -51
Let p and m represent the numbers of miles in the plains and mountains, respectively.
.. p + m = 300 . . . . . . . the whole trip was 300 miles
time = distance/speed, so the trip time can be written as
.. p/90 + m/37.5 = 3 48/60
.. 5p + 12m = 1710 . . . . . . . . . . multiply by 450 to put in standard form
You can solve these two equations by any of several means. The variable p can be eliminated by subtracting 5 times the first from the second.
.. (5p +12m) -5(p +m) = 1710 -5*300
.. 7m = 210
.. m = 30
30 miles of the trip was through the mountains.
Answer:
<u>D</u>
Step-by-step explanation:
The logical step is to <u>factorize the left side of the equation</u>, which becomes:
Then, you can take the square root on both sides.
Not asked, but good to understand the procedure regardless.
