how do i simplify each expression by combining like terms.

Question

i need to know the steps to follow to work out these problems.  Also when they begining with a negative number.  for example, -7(n-1).  i also have other questions for Algebra

 

Thanks

Answer 1

when using the distributive property you have to remember to distribute the -7, so -7(n-1) = -7*n + -7*-1, so it actually equals -7n+7 not  -7n + 1, so if the equation were -7n + 7 = 0 then the next step would be to subtract 7 from both sides in order to isolate the variabe so -7n = -7, and then divide both sides by -7, so n actually equals 1 not 1/7.

Answer 2

Kailee,

Inthe case of

-7(n-1) you use the distributive property. so

-7*n + -7*-1

the coefficient of n is +1 so a negative time a positive is a negative, while a negative time a negative is a positive.  Thus we get
:

-7n+1

now if say -7n +1 = 0 then

you would have two options

the first is to add 7n to each side and the second is to subtact 1 from each side so you get

1=7n (first way)

and

-7n =-1 (furst way)

In either case divide by the coefficient of n to get

n= 1/7

When simplifying always look at a way to mover terms such that you isolate term that you want to solve for and most importantly what operation you perform to one side of the equation you perform the same operation to the other side.  Finally be careful of sign as you have noticed. You could have multiplied the original equation by -1 but that is trick for beginners so it is best to work it as I have.

Hope that helps!
Art