Need help ASAP! WIth2 MAth problem .?WHOEVER ANSWER THIS GETS 10PTS!?

Question

The problems are
What operation in arithmetic represents each of the following?
1) Decreased by
2)sum of
3)increased by

The second problem is
A car rental agency charges $40 per day and $0.20 a mile for each mile over 100 miles. If the charge for one day rental was $70, how many miles was the car driven?
How do you write an equation to solve this problem?
Write and solve this equation.
Is the solution of this equation of the solution of the problem? Why?

THANKS IN ADVANCE!

Answer 1

1) subtraction
2)addition
3)addition

$70-$40 = $30 in per mile
30/.20 = 150 additional miles

100 + 150 = 350 miles

Answer 2

Part 1
subtraction
addition
addition

Part 2
equation

70 = 40 + .20(x)
x represents the unknown number of miles.

Solution: 30 divided by .20 or 150. The car was driven 150 miles total, 50 excess miles.

Answer 3

1. -
2. +
3. +

let x=#miles driven
40 + .20x = 70
(-40)40 +.20x =70(-40)
.20x=30
(1/.20).20x = 30(1/.20)
x = 150
# miles driven = 250 (first 100 miles are free)
the solution to the equation is NOT the solution of the problem because
x solves for the number of miles charged for, not the number of miles driven. The first 100 miles are free

Answer 4

1) Subtraction 2) Addition 3) Addition

Let x = miles driven in excess of 100 miles.
40 + .2x = 70
.2x = 30
x = 150
Total miles driven = 150+100 = 250
Solution of equation gave us the number of miles in excess of 100 miles.
To get answer to problem we had to add 100 miles to the equation solution.