9x^2 -c =d
add c to each side
9x^2 = c+d
divide by 9
x^2=(c+d)/9
take the square root on each side
x = +- sqrt ((c+d)/9)
simplify
x = +- 1/3 sqrt (c+d)
Answer: 1/3 sqrt (c+d), - 1/3 sqrt (c+d)
Answer:
y = 2x
Step-by-step explanation:
Slope = 
Vector

.

. So the sum is

.
For the second, the magnitude is the square root of the sum of the squares of the components. This is equal to

.
5x - 20 = 8x - 65
-20 = 3x - 65
3x = 45
x = 15
Answer:
-5x + 56
Step-by-step explanation:
Use distributive property to refine.
20 - 2x + 36 - 3x
Combine Like Terms
-5x + 56