Geometry Help

Alright guys, this may be super easy as hell for you but Math is my ultimate weak spot and DOES NOT filter through my brain.
I have a better chance of becoming president of the world than ever being a math teacher.


"Solve each equation. Write a justification for each step."

I simply don't know if I should take away 8 from both sides or if I should subtract 1 from both sides. The examples in my math book don't help for crap.
1. 8 - 5s = 1


2. 0.4t + 3 = 1.6


3. 38 = - 3w + 2

Thanks, if you could explain how you did any of the problems that would be amazing.
Thanks in advance.

 

Sure, I'll gladly help. This isn't actually geometry, it's algebra.

1. 8-5s = 1. We NEED to solve for s, to do that we must get S on it's own side, and every other number on the other side of the = sign. Once this happens, we're finished! It's that simple.

Step 1) Subract 8 from both sides. Because there is not an "s" near the 8, 8 will be the easiest number to eliminate. Doing this gives us -5s = 1-8. This is just -5s = -7

Step 2) Lets get rid of that 5, shall we? In order to get rid of 5 infront of the s, we must divide both sides by 5 (since the opposite of multiplication is division). This gives us the equation -s = -7/5 (seven-fifths, the / just means fraction (and fraction just means divide 7 by five).

So we now have -s = -7/5, right? Now, we don't want that s to be negative, so how do we get rid of the negative sign infront of the s? Simple. Multiply by -1 (since a - multiplied by a - is a positive, and since 1 multipled by anything is just the original number (1 x 5 for instance is just 5, we haven't changed it.)

Multiplying -s(-1) = -(7/5)(-1). This tells us that s = 7/5. BAM!


Number 2) I am going to write this is parenthesis notation since you should get used to doing that anyway. It's the same as .4t, only it separates the .4 from the t so you know they are separate terms. It's still the same equation!

(0.4)(t)+3 = 1.6 (if two parenthesis are next to each other it just means multiply those two values, so (2)(3) = ? would just be 2x3, which = 6.)

Now, we have (0.4)(t)+3 = 1.6

Step 1.) Subtract 3 from both sides. Remember, we're solving for t, so in order to do that we MUST get t alone. This gives us (0.4)(t) = 1.6 - 3. This is simplified to (0.4)(t) = -1.4.

Step 2.) (0.4)(t) = -1.4. How do we get the t alone? Remember, t is being multiplied by 0.4, so in order to get it alone we must divide both sides by 0.4. This gives us t = (-1.4)/(0.4) (a parenthesis / parenthesis just means divide the terms, so something like (4)/(2) just means 4/2 which = 2.).

This gives us t = -3.5. Are you starting to understand better?

Why don't you try number 3. Do it step by step. Remember, you goal is to get w alone using multiplication and division. This is a combination of things I did in step 1 and step 2. Write out every step you did below and I will give you comments on them. If you get stuck or need help, my msn is [email protected] or you can just post here and I'll do my best to help you get unstuck.

Write out every step so I can give you comments on every step!

The answer should come out to be w = -12, so you know what you're shooting for.

 

Thanks A LOT! Especially for taking your own time to help me with this.

I think there is a problem with number 2,

You put 1.6 - 3 is 1.4 when it should be 1.3 : P and my answer was t = - 3.2.

I know how to do it again thanks to you.

And I also got w = 12 for the last one. WOOT!

 

1.6-3 is -1.4. Did you mistype it?

 

LOL

 

Ohhhhh! Okay thanks I see what I did wrong after I tried it over. Thanks

 

No problem bud. If you ever need help again, don't be afraid to ask! You can also pm or msn me if you'd like.

 

Alright thank you VERY much

 

Lol :d