SOLUTION: Solve using the addition principle. 2x+8> x +10 The solution set is X X > __ Help me please again I do not understand what I am supposed to do with this.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: Solve using the addition principle. 2x+8> x +10 The solution set is X X > __ Help me please again I do not understand what I am supposed to do with this.      Log On


   



Question 134624: Solve using the addition principle.
2x+8> x +10
The solution set is X X > __
Help me please again I do not understand what I am supposed to do with this.

Found 2 solutions by solver91311, vleith:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
2x%2B8%3E+x+%2B10

You can add -x to both sides:

2x-x%2B8%3Ex-x%2B10

x%2B8%3E10

Then add -8 to both sides:

x%2B8-8%3E10-8

x%3E2

Since we never multiplied or divided by a negative number, the sense of the inequality remains the same throughout.

The solution set is {x|x > 2}

Sanity check:
Pick a number larger than 2 and substitute:
3 is larger than 2:
2%283%29%2B8%3E%283%29%2B10
14%3E13, true statement -- so far so good.

Pick a number smaller than 2
1 is smaller than 2:

2%281%29%2B8%3E1%2B10
10%3E11, false statement, as expected.

The above does NOT conclusively prove the answer, but it does give you a nice warm fuzzy feeling that you are most likely correct.

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Given:2x%2B8%3E+x+%2B10
2x%2B8%3E+x+%2B10
2x+-x+%3E+10-8
+x+%3E+2+
As long as you just add or subtract, the 'less than' sing stays pointing the same direction. If you multiply or divide by a negative number, you need to reverse the sign (less then become greater than) on a negative