Answer:
2.4 hours
Step-by-step explanation:
David's time = 6 hours
Anthony's time = 4 hours
the combined time is given by the following formula
1/ (david's time) + 1/(anthony's time) = 1/total time
1/6 + 1/4 = 1/Total
4/24 + 6/24 = 1/Total
10/24 = 1/ total (taking reciprocal of both sides)
24/10 = total
total time = 24/10 = 2.4 hours
N - the number
14 + n = 17 |subtract 14 from both sides
n = 3
Two lines are perpendicular if and only if the product of their slopes is - 1.
So, you just need to find the slope of each line and find out the product of their slopes.
I will do one example for you.
L1: y = 3x + 5
L2: y = - 3x + 14
L3: y = -x/3 + 14
The slope of a line is the coefficient of the x.
So the slopes are:
L1: slope 3
L2: slope -3
L3: slope -1/3
So now multiply the slopes of each pair of lines:
L1 and L2: 3 * (-3) = - 9 => No, they are not perpendicular
L2 and L3: (-3) * (-1/3) = 1 => No, they are not perpendicular
L1 and L3: (3) * (-1/3) = -1 => Yes, they are penpendicular.
Answer: 9x^4
Using the rules of exponents multiply the -3 times the -3 which equals 9 canceling out the negatives. Then you have that other ^2 but you also had the other one so you still have to keep it which equals that ^4.
