Answer: x = 7, x = -1
Step-by-step explanation: Move the term to the left side
x^2 + 2x - 7 = 8x
x^2 + 2x - 7 - 8x = 0
Combine like terms
x^2 + 2x - 7 - 8x = 0
x^2 - 6x - 7 = 0
x^2 - 6x - 7 = 0
a = 1
b = -6
c = -7
x = -(-6) + (-6)^2 - 4 x 1(-7)/ 2 x 1
Evaulate the Exponent
Multiply the numbers
Add the numbers
Evaluate the square root
Multiply the numbers x = 6 ± 8/2
To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.
x = 6 + 8/2
x = 6 - 8/2
Rearrange and isolate the variable to find each solution
x = 7
x = -1
The fourth side = f, now let's solve for f
value of fourth side = f = 96 km
Answer: 
Step-by-step explanation:
We know that:

Where "d" is distance, "r" is rate and "t" is time.
Solved for the time "t":

The first step is to convert the distance from miles to feet.
Since
, we get:

Knowing that:

We can substitute values into
in order to find the time in seconds:

Since:

The time in minutes is:

First, solve the exponent part because it has a higher precedence than multiplication. And we have a negative exponent. Which means we takes the reciprocal of 4 then take to the power of 4.
4^-4 = 1/4^4 = 1/256
Now do the multiplication part.
16 * 1/256 = 1/16