Step-by-step explanation:
4 + x + 3x = 4 ( 5x ) - 3 ( x ) - 10
4 + x + 3x = 4 + 5x - 3 + x - 10
x + 3x + 5x + x = 4 + 4 - 3 - 10
10x = 21
10x % 10 = 21 % 10
x = 2,1
Are the directions asking you to solve these ?
Answer:
tangent: y-
= -4(x -
)
Step-by-step explanation:
differentiating

isolating y' to one side and simplifying


when x =
,
y' = 
y' = 
tangent: y-
= -4(x -
)
Givens
Slower plane
r = r
t = 2.5 hours
d = d
Faster Plane
r_faster = 1.5 * r
t = 2.5 hours
d1 = d + 127.5
The time is the same for both
t = d/r
d1/r1 = d/r
(d+ 127.5)/1.5r = d/r Multiply each side by r
(d + 127.5)/1.5 = d Multiply both sides by 1.5
d + 127.5 = 1.5d Subtract d from both sides.
127.5 = 1.5d - d
127.5 = 0.5d Divide by 0.5
127.5 / 0.5 = d
255 = d
Now you can go back and figure out the rates.
First find d1
d1 = d + 127.5
d1 = 255 + 127.5
d1 = 382.5
<em><u>Rate of the slower plane</u></em>
d = 255
t = 2.5 hours
r = d/t
r = 255/2.5
r = 102 miles per hour.
<em><u>Faster plane</u></em>
d1 = 382.5 miles
t = 2.5 hours
r1 = d/t
r1 = 382.5/2.5 = 153 miles per hour.