Maths - Equations 11 Cred For Each Answer And Meth

Woops! I didn't see the parenthesees there.

 

I got four and five explained to ya I think.

 

1. 3X +7 =15

subtract seven from both sides, then divide both sides by 3, resulting in 4.

2. 4(x-7)=-3

distribute to get 4x-28 = -3, then add 28 to both sides, then divide by 4, resulting in 25/4

3. (9-4x)(3) = 4

multiply both sides by 3, then subtract 9, resulting in 3 = -4x, then divide the -4 to get x = -3/4

4. combine all x terms to get 4x = -12, divide by four and achieve
x = -3

5. distribute, getting 12x -8 = 7x +7
then combine x's, and get 5x = 15, so x =3

6. first distribute.
8x +12 + 3x -15 = 6x -6
combine x terms; 5x = -3, so x = -3/5

7. (2x-7) times (1/5) = 3-4x

first multiply both sides by 5, achieving 2x - 7 = 15 - 20x
then combine x's to get 22x = 22, and so x = 1

8. make the first term in terms of x only.

x = (13+3y/
substitute this into the second equation, achieving:

6[(13+3y)/] - 5y =18

this equals (78 + 18y)/8 - 5y = 18
simplified, 78 +18y -40y = 144
combine y's, so -22y = 66
y = -3

 

ack i forgot to resubstitute y back in to determine x.

for the last problem x = (1/2)

 

heres 8 in detail

Original:
8x - 3y = 13
6x -5y = 18

Linier combination method

6(8x - 3y = 13) = 48x - 18y = 78
-8(6x -5y = 18) = -48x + 40y = -144

(48x - 18y = 78)
+(-48x + 40y = -144)
------------------------
22y = -66
-66/22 = -3
y = -3

Sub y in original problem

8x - 3(-3) = 13
8x + 9 = 13
8x = 4
x = .5

 

pssssh, linear combo is for newbs. cancellation or substitution ftw

 

linear combo is easier for that prob didnt feel like subing

 

DoNE ! it's all good ... awayting creds ... if i get

 

It really depends on whats easier for the person. Also they teach it differently in different countries.

 

lol........maths homework ?

 

He has them all done people so dont respond. He will send creds accordingly to who helped the most and who gave him the answers and methods first.

 

THanks For Your Help Every1

These Rewards go like this

AngelX = 11Creds for No.1
Nielz = 22 Creds For No. 2 + 3
JoeBum14 = 22 Creds For No. 4 + 5
Wender = 11 Creds For No. 6
stott = 11 Creds For No. 7
ixiix = 24 Creds For No. 8

Thanks Alot Peoples

 

Thanks for the creds man.

 

Bah, I should post some of my maths homework (or what they call coursework) on here and see you all struggle.

Just too show u a degree level question from my coursework

Without using l'Hopital's rule, find
(a) lim (x->3) of ((x^2)-4x+3)/(x^2)-7x+12

(DO NOT ATTEMPT BTW)
Daz

 

Hey, I'm jsut about to learn limits! Check back in a month or two, I might have it.


(x-1)/(x-4) ; basically the answer is anything under -2 (?). I'm probably completely wrong, but this is just two quadratics right over each other, right?