2 algebra 1 problems for some reason i cant get! lol

[smelliot]

-n + .4n + 1.8 = -3 ...i know the answer is 8, but cant seem to come to that conclusion myself.

also, 5(x-2) - (-x + 3) = 7 ...i know the answer is 10/3 but cant seem to get there on my own either.
Thanks in advance

 

[Mrspi]

-n + .4n + 1.8 = -3 ...i know the answer is 8, but cant seem to come to that conclusion myself.

also, 5(x-2) - (-x + 3) = 7 ...i know the answer is 10/3 but cant seem to get there on my own either.
Thanks in advance

For the first problem, remember that if there is NO numeric coefficient written, we ASSUME that coefficient is 1. So, for example, x means 1x, and -n means -1n.

So.....
-n + .4n + 1.8 = -3
means
-1n + .4n + 1.8 = -3

Combine like terms on the left side....(-1 + .4)n + 1.8 = -3
And continue from

For the next problem, remember that you could write that subtraction as "adding the opposite." And, that "the opposite" of something is -1 MULTIPLIED times that something.

So, 5(x-2) - (-x + 3) = 7
means

5(x - 2) + -1(-x + 3) = 7

Multiply each term inside the parentheses by the factor outside:

5*x - 5*2 + (-1)*(-x) + (-1)*3 = 7

and take it from there.

If you're still having difficulty with these, please repost and show us what work you've done for the "take it from there" part.

 

[HallsofIvy]

-n + .4n + 1.8 = -3 ...i know the answer is 8, but cant seem to come to that conclusion myself.

I presume you know that "-n" is the same as "(-1)n" and that, by the "distributive law", (-1)n+ .4n= (-1+ .4)n= -.6n. So the equationis the same as -.6n+ 1.8= -3. Now subtract 1.8 from both sides: -.6n= -4.8 and, finally, divide both sides by -.6.

also, 5(x-2) - (-x + 3) = 7

...i know the answer is 10/3 but cant seem to get there on my own either.
Thanks in advance

Again you need the "distributive law". 5(x- 2)= 5x- 10 and -(-x+ 3)= -(-x)- 3= x- 3. Using those, the equation becomes 5x- 10+ x- 3= 7. Of course, 5x+ x= 6x and -10- 3= -13 so that is 6x- 13= 7. Adding 13 to both sides gives 6x= 20 and then divide both sides by 6.

 

[smelliot]

thanks!

Thank you so much. Yeah, umm....user error (lol)...
for the first problem, i didnt utilize correct subtraction if you can believe that, lol, and thought that taking 1 from .4 gave me -.4.... yeah we wont talk about that hahaha...

In the second problem, i did not reverse what was in the paragraph completely but only made the -x a positive (because of the double minus signs), however I didnt make the 3 in the paragraph a -3, so that's where my problem was there. dang.

"In all your getting, get understanding"-God
Thanks so much for your help!!