Remember you can do anything to an equation as long as you do it to both sides
x+9=18-2x
add 2x to both sides
2x+x+9=18+2x-2x
3x+9=18+0
3x+9=18
minus 9 both sides
3x+9-9=18-9
3x+0=9
3x=9
divide both sides by 3
(3x)/3=9/3
(3/3)x=3
1x=3
x=3
X + 9/7 = 10
- 9/7 -9/7
___________
x = 8 2/7
Just look it up you can find the answers you are looking for
Answer:
Original Salary: 
Increase in 3%: 
Step-by-step explanation:
So when something increases by x%, the new value is (100+x)% the original value. So 6255, is 105% the original value. This means to find the original value, we have to find the number that has 6255 as 105% of it's value. Whenever you try to find x% of a number, you multiply it by the decimal value of the percentage, which is found by dividing by 100. So to find x%, you do: 
where o = original value, x=percent. In this case the percent is 105%, which when divided by 100 is 1.05. So this gives us the equation: 
. This is his original salary. You need to do this process, do not make the mistake of subtracting 5% from 6255. This is because 5% of 6255 does not equal the 5% of the original value. 5% of 6255 should be greater than 5% of the original value, since the new value is an increase of 5%. So since we have his original salary, we can calculate the salary increase had it been 3%. to do this we multiply by 1.03 (103% divided by 100). This gives us the equation: 
