maths question for school urgent!!

hey i got 3 questions on an assignment, which i don't know how to do can anyone help me. they all need simplifying

a) 10y + (y-+7)(y-5) + 4y(to the power of 2)

b) 7z - (4a - 2z) - 6a(3a + 4z)

c) 4m(to the power of 2) - (10m + 4) to the power of 2

thanks to anyone who can answer and explain!

A) 10y+(y-7)(y-5)+4y^2 (note that the little carrot -shift 6- means raised to the power of)

First we take care of the parentheses.
So, (y-7)*(y-5)= y^2-12y+35 Since I have no knowledge of what you do and do not know, I will explain this. The method is called FOIL. (acronym for first outside inside last) you take the first term in both factors, y and y, and multiply them together. So that's y^2. Then you take the outside terms of each. y and -5, and multiply them together. So far we have y^2-5y. Then we take the inside terms, -7 and y, and multiply them together. That gives us -7y. So now we have y^2-5y-7y. Then we take the last term in each factor and multiply them. -5 and -7. That gives us +35. So we combine like terms and it comes out to y^2-12y+35.

So the full equation now looks like this: 10y+y^2-12y+35+4y^2. So now it's just a matter of combining like terms.

4y^2 and y^2 add up to 5y^2. 10y and -12y add up to -2y. And 35 has no like term.

This sets your equation up as 5y^2-2y+35. This answer cannot be factored, so I'm pretty sure you can leave it as is.

I'd help with B and C, but I have my own homework to attend to. Sorry.

Alright, it's a lot easier than it seems. Trust me. I'm not going to do all of the work for you, because that completely defeats the purpose of homework, but I will try to explain it to you the best that one can over the internet.


Question A) So, first you want to FOIL (First, Outer, Inner, Last) the (y-70)(y-5). So that means you multiply the first y by the second y, getting y (to the power of 2).

Then you multiply the y by the -5, getting -5y.

Follow these steps with the -7. When you're done, your problem should look like this:

10y+[y(to the second power)-5y-7y+35]+4y(to the second power).

The numbers in the brackets are the ones that you should have solved for using the FOIL method. Don't actually write them down in your homework, because you're teacher will wonder what they're there for.

Add all similar numbers (all y's with each other, all y's (to the second power) together, etc.).

The rest should be self explanatory. Just be sure to organize it from most exponents to least, and numbers with variables always go before numbers without variables.


Question B) This one is a bit easier. Just multiply whatever is outside of the parenthesis with what is inside the parenthesis.

NOTE: -(4a-2z) becomes -4a+2z. This is because the negative (the minus sign) is outside the parenthesis and therefore multiplies with whatever is inside the parenthesis. Since there isn't a number outside the parenthesis, it is implied that it is a 1. Because of the minus sign, it is a -1.

Also, watch the minus sign before the -61 when you're multiplying.


Question C) So for this one, you've got -(10m+4) to the power of two. So you think it would become 100m (to the power of 2)+16.

WRONG.

It actually becomes - (10m+4)(10m+4). So what does this mean? You guessed it: FOIL. Follow the steps that I explained in part a, and you should (hopefully) get -100m (to the power of 2)+80m+16. From there, add or subtract the like numbers (so you should add the 4m (to the power of 2) to the -100 m(to the power of 2), getting -96m (to the power of 2)). From there, simplify and you should be done!


Hope this helps! If you still need help, don't hesitate to ask.

thanks guys alot. I kind of new how to do it but wasn't 100% sure. Thanks alot though. just been doing my math for 3 hrs almost finished saved all the ones i couldn't do just need help with 2 more questions if thats ok.

a) 4-(g+2)/5 = 2 + g-3/4

what does g =?

b) I think of a number, add three, divide the result by six and end up with an answer that is 19 less than the number I first thought of. Find the number I first thought of.

Thanks again guys!

Originally Posted by masterswordhero

a) 4-(g+2)/5 = 2 + g-3/4

Is that g-3/4 (as in g minus .75) or g-3 divided by four (as in (g-3)/4).

And may I remind people, you aren't allowed to give away answers. You can help people by teaching them, and giving them examples (please no examples that are too similar to the problem, like replacing just one number).

Rising Light had the right idea...just use different numbers so that masterswordhero (or any other member that comes for help) can do the work on his/her own.

-BGS

[QUOTE=masterswordhero;1970517]
a) 4-(g+2)/5 = 2 +g-3/4

Ok, first you would distribute the parentheses on the left. You would end up with 4-g-2/5=2+g-3/4
Now I'm having the same trouble here as BGS. Can you possible MS-Paint a crude drawing of what the exact problem is so we can help you better?

b) I think of a number, add three, divide the result by six and end up with an answer that is 19 less than the number I first thought of. Find the number I first thought of.

Algebra is always easier for me. So here's an equivalent problem:

Solve for x.

(x+3)/6=X-19

Does that make it any easier? Just try and solve it algebraicly from there. I don't want to do the problem any more for fear of giving away too much. As BGS said, we're not allowed to give answers.