Can anyone help my daughter with 8th grade math?

Question

I don't understand this and neither does she. If you could explain how to work out these equatios would be greatly appreciated.

SIMPLIFY THE EXPRESSION
1. 9+4r-7

2. 5+(-12t )+ 8t

Answer 1

9 + 4r -7= 0
-9 -9

4r - 7 = -9
+7 +7

4r = -2

4r/4 = -2/4

r= -2/4 reduce it by dividing the numerator and denomenator by 2

r = -1/2(solving for r) or you could just leave it as 2+4r(simplify)


5 + (-12t) + 8t= 0
-5 -5

-12t + 8t = -5

-4t = -5

-4t/-4 = -5/-4

t= 5/4 reduced by dividing 4 into 5

t= 1 1/4(solving for t) or leave it as 5-4t(simplify)

Answer 2

1. You have three terms: positive 9, positive 4r, and negative 7
you can combine the 9 and the negative 7 because they are "like" terms. 9 and negative 7 = 2. Basically 9-7.

The positive 4r cannot be combined with the 9 or 7 simply because of the "r". It can only be combined with another number that is followed by an "r".

So now we have 4r+2.

In some cases they might want you to solve for "r" but I think in thisa case we are done.

2. Try this one by yourself. You have three terms again:
positive 5, negative 12t, positive 8t

You can't do anything with the 5, but the terms that have "t"s can be combined.

Answer 3

These are not equations, they are expressions. Equations have an equal sign.

You must regroup like terms. In the first one, rewrite it

9 -7 +4r, then group the numbers (9 -7) +4r . You get 2 +4r

In the second, just group the t terms 5 + [-12t +8t]. You get

5 + -4t or 5-4t

Answer 4

You have to separate the equations into what you do know, and what you don't know. Variables (4r in question 1) you do not know. So leave that be. But you can simplify the rest by combining +9 and -7, thus you have +2. The simplified expression in question 1 would be: 4r + 2.

Question 2: You have two indentical variables, so you can combine them to form one variable: -12t + 8t = -4t. the simplified expression would be: 5+(-4t).

Let me know if you need more explanation. [e-mail]

Answer 5

you have to "solve" each expression as much as you can!...

1) 9 + 4r -7 = 9 - 7 +4r, so it is reduced to 2 + 4r

2) 5 +(-12t) +8t = 5 - 12t +8t (becasuse sign laws) = 5-4t

Answer 6

1) Combine like terms:
9 + 4r - 7
(9 - 7) + 4r
2 + 4r

2) Combine like terms
5 + (-12t) + 8t
5 - 12t + 8t
5 + (-12 + 8)t
5 + (-4)t
5 - 4t

Answer 7

In a hurry, but heres a few: Im 13 too, but in 9th grade math: 19. Solid means the point on the line is a solution, and a dotted is that the point on the line is not included in the solution. 20. Because If y equals something, it is horizontal. So the space in between the two horizontal lines is the solution on the graph??? idk, i think so, but not really sure. omg gotta go prob didnt help at all but it was a good try:):)

Answer 8

My son had, had problems with his math (7th grade) and also I couldn't help him. I contacted his teacher and told her that I was not able to understand this kind of math and if she could please help him. She has. I told my son that if he didn't understand how to do a problem, that he needed to ask her and to take notes when she was going through a problem, so that he could use it for reference later. He now asks her for help and has been able to get A's. He has learned that asking the teacher is the best way to understand the way to do math. Once he understands the way a problem works, he's got it.
We can't learn this math for them. They have to learn skills, like taking notes and asking questions to be able to do it. Have her go ask her teacher after class. It is the only way she will learn to help herself.

Answer 9

1. 2+4r
2. 5+(-4t)

Answer 10

simplify...

2+4r

2. 5+(-4t)

just combine like terms