Answer:
0.081,0.2621,0.645,0.919
Step-by-step explanation:
Let X be the average speed of a car driving down freeway
Given that X is normal with mean as 70mph with a standard deviation of 5mph.
To convert to Z score we do

a) the probability that a randomly selected car is driving more than 77mph

b) probability that a randomly selected car is driving between 65 and 69 mph
= 
c) the probability that a randonly selected car is driving between 67 and 77mph
=
d) the probability that a randomly selected car is driving less than 77mph

Assuming the exponent is supposed to be "^2" your equation will read:
4x² + 8x - 5
It must set equal to y to be a valid function and the y must be set equal to zero to find x-intercepts.
4x² + 8x - 5 = 0
4x² - 2x + 10x - 5 = 0
2x(2x - 1) + 5(2x - 1) = 0
(2x + 5)(2x - 1) = 0
Set each binomial equal to zero.
2x + 5 = 0
2x = 0 - 5
2x = - 5
Divide both sides by 2
x = - 5/2
2x - 1 = 0
2x = 0 + 1
2x = 1
x = 1/2
Your x-intercepts are x = - 5/2, 1/2 or (- 5/2, 0) and (1/2, 0)
1.3n (it can be simplified like any other equation just add like terms and remember there is a one before every variable)