I need help with a few Algebra problems?

Question

1. Use the Substitution method to solve this system of equations.
s + 2t = 1
3s + t = -7
2. Choose a method and solve.
6x - y = 9
3x + 4y = -9

3.The perimeter of a rectangle is 120 feet. The length is three times the width. Find the length and the width.(Use a system of equations.)
Solve
4. -3(6+1)
5. 4(-1) with a 4 on the top of the )
6. 8(81) with a tiny zero in top of the 81
7. Solve 3x + 2y= for x in terms of y
8. Solve 3x + 2y = 9 for y in terms of x
the reason i need help with all those os because ive taken the course three times and failed so im just trying to comprehend using these practice problems so if i seem dumb to any of you sorry.

Answer 1

You're NOT dumb! Everyone has different skills. Thought you were going to send me a note when you got stuck?? I took alg II twice!

1. simply switch it to s=1-2t. Now put that first one into the second , for s, which will give you the value of t when you solve it. Plug in t's value into either and that will give you s.

2. do the same way

3. P=120
L=3w
P=L times W

4/5: take the number on the outside and multiply each number inside the (), then combine.

7/8: isolate the variable (letter) and get it just on one side

Answer 2

You're not dumb! It's great that you are working on practice problems. The more practice you get, even if it's just looking at how others have solved things, the better you will understand it.

It would be nice if you could include your attempts at answering so that we can get a better idea of where your specific difficulties are. That way you'll get information you might need to understand better.

So I have some questions for you related to your questions:

1. Do you know what the substitution method is? How much of it do you understand?
2. Which methods do you have to choose from?
3. You need to create a variable for unknowns in questions like these, usually by taking the first letter of the word representing information. "The (L)ength is [=] 3 times the (w)idth." or L=3w.
Do you know what the perimeter is? Do you know an equation for determining the perimeter?

4. You need to learn about the distributive property.
http://www.algebrahelp.com/lessons/simplifying/distribution/

5. You mean you have an exponent of 4? Do you understand how to break down a term with an exponent? For example, 3^5 is 3x3x3x3x3.

6. Do you know what every single number to the power of 0 is? 1! Let me show you why:

2^4=2x2x2x2=16
Let's divide that by 2. Now we have:
2^3=2x2x2=8
Let's divide that by 2:
2^2=2x2=4
Let's divide that by 2:
2^1=2
Let's divide that by 2:
2^0=1

No matter which number you have, a 0 exponent means that the number is 1.

7/8. When they say things like "solve for x", it means you want to end up with x=blahblah. Solve for y means y=blahblah. You follow the same steps you would for an equation that doesn't have two variables, you'll just have an answer with a variable in it.

Answer 3

the first two are systems problems,

so substitute the "s" in the second equation with an isolated "s" in teh first equation to get:

3(1 - 2t) + t = -7 and solve for t then pluge this answer into the first equation to solve for "s".

the same process goes for the second question.

#3: Let x be width, then 3x be length:

2(x) + 2(3x) = 120 feet solve for length and width

etc.

Answer 4

You are NOT DUMB
These are rather simple equations, really
Do you want to know why you cannot pass this portion of the test?
You do not understand the principles of algebra, multiplicative property, distribution, or substitution.
And you do not CORRECTLY understand Order of Operations.
Which happens first? the exponents? the Parenthesis?
Most any regular to this forum can give you the answers, what YOU NEED to do is, learn (or re-learn) the basics of algebra and the order of operations

When you have these understood, you can do these questions fairly easy
Until you are much more comfortable with your 'algebra' ALWAYS double check your answers by SUBSTITUTING them back into the original question
good luck , YOU can do this!!