Answer:
Step-by-step explanation:
d = r * t
Let the time at 59 miles / hour be t
59*t + 57* (4.5 - t) = 259.5 Remove the brackets
59*t + 256.5 - 57*t = 259.5 Combine the left
2t + 256.5 = 259.5 Subtract 228 from both sides
2t = 259.5 - 256.5 Combine
2t = 3 Divide by 2
t = 1.5
So he spent 1.5 hours going at 59 miles per hour
He spent 4.5 - 1.5 = 3 hours going 57 miles per hour.
Answer:
b
Step-by-step explanation:
There is no common term
Between 2l and l its l
Between 2l and 2 its 2
Between 2 and l there are no common terms, so between 2 l and 2l also there are no common terms
Answer:

Step-by-step explanation:
Standard equation of a line is y = mx + b, where m is the slope.
Given line y = - 3x + 78, slope, m₁ = -3
<em><u>To find the line perpendicular to the given line.</u></em>
The lines are perpendicular to each other if the product of their slopes = - 1
That is,

So the slope of new line is

