Equation in <span>slope intercept form
y = -7x + 6
hope it helps</span>
Let the base of the ladder be x ft and the extension be y ft.
"when fully extended, a ladder is 28 feet in length."
means: x+y=28
"<span>the extension is 4 feet shorter than the base</span>"
means: y=x-4, that is x-y = 4, (taking y to the side of x, and -4 to the other side of x and y)
thus, we have the system of equations:
1) x+y= 28
2) x-y=4
adding the 2 equations, we have:
(x+y)+(x-y)=28+4
2x=32
x=32/2=16
x+y=28, so 16+y=28, thus y=12
Answer: Base: 16, Extension 12
The y-value changes sign when a point is reflected across the x-axis. The reflected point is (-3, -7).
Answer:
0.1199 = 11.99% probability that at least 5 of them did not finish the marathon
Step-by-step explanation:
For each runner, there are only two possible outcomes. Either they finished the marathon, or they did not. The probability of a runner completing the marathon is independent of any other runner. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
97.4% finished:
This means that 100 - 97.4 = 2.6% = 0.026 did not finish, which means that 
100 runners are chosen at random
This means that 
Find the probability that at least 5 of them did not finish the marathon
This is:

In which









0.1199 = 11.99% probability that at least 5 of them did not finish the marathon