The slope of y= x+5 is m =1
y = - 5
substitute the value of x = 4 into the equation and solve for y
- 12 + 9y = - 57 ( add 12 to both sides )
9y = - 45 ( divide both sides by 9 )
y =
= - 5
The answer is 90 miles per hour.
First, find the gradient/slope:
Use slope formula:
m=(y2-y1)/(x2-x1)
=(11-5)/(3-1)
=6/2
=3
Then use the line equation formula:
y=mx+c
You can substitute (1,5) if you like, also must substitute the slope as well!
5=3x1+c
c=2
Then find the full equation, which gives you the answer:
y=3x+2