<span>Simplifying
0x + 7 + 5x = 2x + 30 + 40
Anything times zero is zero.
0x + 7 + 5x = 2x + 30 + 40
Combine like terms: 0 + 7 = 7
7 + 5x = 2x + 30 + 40
Reorder the terms:
7 + 5x = 30 + 40 + 2x
Combine like terms: 30 + 40 = 70
7 + 5x = 70 + 2x
Solving
7 + 5x = 70 + 2x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-2x' to each side of the equation.
7 + 5x + -2x = 70 + 2x + -2x
Combine like terms: 5x + -2x = 3x
7 + 3x = 70 + 2x + -2x
Combine like terms: 2x + -2x = 0
7 + 3x = 70 + 0
7 + 3x = 70
Add '-7' to each side of the equation.
7 + -7 + 3x = 70 + -7
Combine like terms: 7 + -7 = 0
0 + 3x = 70 + -7
3x = 70 + -7
Combine like terms: 70 + -7 = 63
3x = 63
Divide each side by '3'.
x = 21
Simplifying
x = 21</span>
The answer is D because -10+(-40)+(-90) is the same just swiched
Answer:
The answer is below
Step-by-step explanation:
a) Let x represent the time taken to drive to see the relatives and let d be the distance travelled to go, hence:
60 mi/h = d/x
d = 60x
When returning, they still travelled a distance d, since the return trip takes 1 h longer than the trip there, therefore:
40 mi/h = d/(x+1)
d = 40(x + 1) = 40x + 40
Equating both equations:
60x = 40x + 40
60x - 40x = 40
20x = 40
x = 40/20
x = 2 h
The time taken to drive there = x = 2 hours
b) The time taken for return trip = x + 1 = 2 + 1 = 3 hours
c) The distance d = 60x = 60(2) = 120 miles
The total distance to and fro = 2d = 2(120) = 240 miles
The total time to and fro = 2 h + 3 h = 5 h
Average speed = total distance / total time = 240 miles / 5 h = 48 mi/h
<u>Answer:</u>

<u>Explanation:</u>
Before we begin, remember that:
(
)ⁿ = 
This means that power is distributed in case of division
The given is:

Applying the above rule, we would get:
= 
Hope this helps :)