Pm me i ne more info,,, is there some missing ?
Answer:
The speed is equal to 
Step-by-step explanation:
we know that
The speed is equal to divide the distance by the time
Let
x------> the distance in miles
y-----> the time in hours
s----> the speed in mph
so

In this problem we have


substitute

Answer:
That is asking you to find the sine of (3/4) PI radians.
If you look at the attached graphic, you will see that (3/4) PI radians = 135 degrees
Going to this calculator, we see that the sine of 135 degrees is 0.70711
https://www.1728.org/trigcalc.htm
Step-by-step explanation:
Step-by-step explanation:
Let's combine the like terms first, which are x^2 & -3x^2, and 3x & -4x.
x^2 -3x^2 is -2x^2. 3x -4x is -x.
The final, simplified expression would be -2x^2 -x.