<span>Chris' average speed is 3.5mph:
Lets take Chris' brother speed = B
then Chris speed = (B+ 1) mph-------given in the question
and:
The average speed for covering 18 miles= chris' average speed + his brother's
average speed = (B+ 1) + B
since Speed = Distance covered / time taken
then average speed for 18 miles can also be found by: 18 miles/3 hours = 6 miles per hour
then we have; (B+ 1) + B = 6mph
(B +1) = (6-B)
B+B = 6-1=5
2B=5
B=5/2=2.5 mph (this is Chris' brother average speed)
Hence Chris' average speed is = B+1= 2.5+1= 3.5mph</span>
The angle would be the tangent.
Tangent ( angle) = opposite leg/ adjacent leg
Tangent angle = 28.4/100
Angle = tan^-1(28.4/100)
Angle = 16 degrees
5X-20=4X+7
5X-4x=20+7
X=27°
You can use the formula y1-y2=m(x1-x2)
to find m, you just do (y2-y1)/(x2-x1) so....
(115-80)/(80-40)= 35/40= 7/8
then plug it into the point slope equation:
y-115=7/8(x-80)
y-115=7/8x-70
y= 7/8 x + 45
