SOLUTION: I have been working on this problem for a while and have gotten several different answers. 0.4x + 3 ≤ 0.8x – 6 I believe solving is easier if I get rid of the decimal

Algebra ->  Inequalities -> SOLUTION: I have been working on this problem for a while and have gotten several different answers. 0.4x + 3 ≤ 0.8x – 6 I believe solving is easier if I get rid of the decimal      Log On


   

Question 147824: I have been working on this problem for a while and have gotten several different answers.
0.4x + 3 ≤ 0.8x – 6

I believe solving is easier if I get rid of the decimals by multiplying by 10. Do I multiply every term by 10 or only the terms with decimals?
0.4x + 3 ≤ 0.8x – 6
40x + 30 ≤ 80x – 60
Subtract 80x from both sides
-80x + 40x + 3 ≤ - 60
Subtract 30 from both sides
-80x + 40 x ≤ -60 – 30
-40x ≤ -90
Flip the inequality sign around because I am dividing by a negative number
-40x ≥ -90
x = -90 divided by -40
or 2.25
I this correct?
Thank you very much



Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Remember you can always check whether your answer is correct by plugging it back into your original equation.
0.4x%2B3%3C=0.8x-6
0.4%282.25%29%2B3%3C=0.8%282.25%29-6
0.9%29%2B3%3C=%281.8%29-6
3.9%3C=-4.2
Your answer led to a false statement.
It is not correct.
0.4x%2B3%3C=0.8x-6 Multiply by 10, that's a good idea.
4x%2B30%3C=8x-60<--- This is the line where you made your mistake
Yes, you need to multiply each term on both sides by 10.
You made a small multiplication mistake on both sides.
10(0.4)=4, you had 40.
10(0.8)=8, you had 80.
I think you can take it from there and finish it.
Please re-post if you need any more help.