Posted by **B.B.** on Monday, March 1, 2010 at 4:59pm.

Could someone please help me with this math problem?

Solve using the multiplication principle. Give the answer in set-builder notation.

-4/5 less than or equal to -8x.

I want to say that I multiply both sides by 5 but I'm not sure. I'm confused with this problem.

Thanks.

- Math -
**bobpursley**, Monday, March 1, 2010 at 5:08pm
you are trying to solve for x. How does multiplying by 5 do that? Why not start by multiplying by 1/8? You do have one more step.

- Math -
**Reiny**, Monday, March 1, 2010 at 5:08pm
go with your instinct

-4/5 ≤ -8x

times by +5

-4 ≤ -8x

"move" the terms

8x ≤ 4

divide by 8

x ≤ 1/2

remember you switch the inequality sign only if you multiply or divide the inequation by a negative, we multiplied by +8, so it stayed the same.

- ooooppss Math -
**Reiny**, Monday, March 1, 2010 at 5:11pm
forgot to multiply the right side by 5

-4 ≤ -40x

40x ≤ 4

x ≤ 1/10

- Math -
**B.B.**, Monday, March 1, 2010 at 6:32pm
Thanks.

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