ks3 maths question help?? use of symbols?

Question

well the problem is i understood all of this in lesson then as soon as i get to doing the homework i go totally blank :|

please could you justtell me how ot answer these 2 questions plz coz as soon as i know i could do the rest aswel :)

ok the questions are expand and simplify
(3a-b)(2a+b)
and
(6t -2s)(3t-4s)

also could anyone plz tell me how to factorise 5ab + 2b
please dont leave any sarcastic comments or anythin am really stuck :|

thanksthanks thanks lol
this is hard stuff to say im only in year 8!

also this is for tomorro so any help please :D

Answer 1

FOIL

(3a - b)(2a + b) =

6a² - 2ab + 3ab - b²

6a² + ab - b²

- - - - - - - -

FOIL

(6t - 2s)(3t - 4s) =

18t² - 6st - 24st + 8s²

18t² - 30st + 8s²

- - - - - - - - - - -s-

Answer 2

Expanding and then simplifying equations like the first one can be done by what's called FOILing. That stands for "first, outside, inside, last." First you multiply the first item in each parenthesis together, then the outside items, then the inside items, and finally the last items. Like this:
(3a-b)(2a+b)
Multiply the first items: 3a*2a = 6a^2
Outside: 3a*b = 3ab
Inside: -b*2a = -2ab
Last: -b*b = -b^2

Now we combine all the terms (simplify)
6a^2 + 3ab - 2ab - b^2 = 6a^2 + ab - b^2.

There you go. That's what FOILing is.

The second question, factorizing 5ab + 2b, is where you pull out the term that the numbers have in common, and multiply it by the remaining terms.

5ab + 2b becomes b(5a+2)

Answer 3

Remember the FOIL rule..... First times first. Outer times Outer. Inner times inner. Last times last. So for your first example:

First Times First: 3a*2a = 6a^2.
Outer times Outer: 3a*b = 3ab
Inner times Inner: -b*2a = -2ab
Last Times Lat: -b*b = -b^2

add them up: 6a^2 + 3ab + -2ab + -b^2 =
6a^2 + ab -b^2.

now just work your second problem the same way.

for your other question... what is the common factor of 5ab + 2b? it is b. So divide by b and you get 5a+2, so you can express 5ab+2b as b(5a+2).

Answer 4

you have to FOIL - First Outer Inner Last

(3a - b)(2a + b) = First: 3a x 2a = 6a^2
Outer: 3a x b = 3ab
Inner: -b x 2a = -2ab
Last: -b x b = -b^2

= 6a^2 + ab -b^2

same for the second one.

factoring 5ab + 2b:

what do they have in common, in this case only a 'b' term, so factor it out: b(5a +2) that's it

Answer 5

(3a - b)(2a + b) = ............. each part times each part
6a² + 3ab - 2ab - b² =
6a² + ab - b²

(6t - 2s)(3t - 4s) =
18t² - 24st - 6st + 8s² =
18t² - 30st + 8s²

5ab + 2b =
(5a + 2)b ............... just separate out the common factor

Answer 6

jap and American math are an similar. it really is in hassle-free words that once you're making a posting, you'll discover it complicated to sort exponents, so that you aspect out it in a way it really is everyday by maximum folk. interior of an similar way, because you should no longer sort fractions of their customary visual attraction, you in hassle-free words educate them whit branch indications, and grouping indications (hoping that human beings ought to understand you.) It receives worse in case you try to educate integration limits or logarithm bases, Worst nevertheless with determinants and matrices. Welcome to the answer international of mathematics notations. some human beings positioned up their questions int he way you've printed in photobucket. in spite of the indisputable fact that, answerers do not typically answer in pictures.

Answer 7

use the foil method:D its simple and easy to remember!! x