Solve using the addition and multiplication principles. 0.7n-15+n2n-8-0.4n

= 0.7n-2n - 15 + 15 + n - 0.4n 2n-2n - 8 - 0.4n +15 combine like terms
= -1.7 +n 6.6 simply
=1.7n/1.7 6.6/1.7 divide
= n 4.9
Did I do this right? if not what did I do wrong?

Question

Solve using the addition and multiplication principles. 0.7n-15+n>2n-8-0.4n

= 0.7n-2n - 15 + 15 + n - 0.4n > 2n-2n - 8 - 0.4n +15 combine like terms
= -1.7 +n > 6.6  simply
=1.7n/1.7 > 6.6/1.7 divide
= n > 4.9
Did I do this right? if not what did I do wrong?

anonymous · Answer

I think that -0.4n should be a +0.4n in your first step on the left side of the equation.  It should also be removed from the right side of the equation.

anonymous · Answer

wow. so the answer is wrong? Can u show me how to do this right please because I'm confused

anonymous · Answer

Sure!
$$0.7n-15+n>2n-8-0.4n$$The way I'd start is by combining like-terms.
$$1.7n-15>1.6n-8$$Subtract 1.6n from both sides.
$$0.1n-15>-8$$Add 15 to both sides to get rid of the -15.
$$0.1n>7$$Divide both sides by 0.1 (or multiply both sides by 10).
$$n>70$$
Substitute 70 in for n to verify.  
104=104

anonymous · Answer

wow thanks I understand now what i did wrong. i really appreciate your feed back.

anonymous · Answer

No worries.  Let me know if you have any other questions about it.