math
posted by Laura .
Decrease a number by 5, divide the result by 2, then add 17 and multiply by 5. If the final result is 100, with what number did you start?

[( x5)/2 + 17] * 5 = 100
Divide both sides by 5.
(x  5)/2 + 17 = 20
Subtract 17 from both sides.
(x  5)/2 = 3
Multiply both sides by 2.
x  5 = 6
Add 5 to both sides.
x = 11