Binomial formulae Presented by Ian Cathi Dylan and

Binomial formulae Presented by: Ian, Cathi, Dylan and Clara

Contents • First binomial formula + video • Second binomial formula • Third binomial formula + video • Why we should not use BIDMAS • Quiz • Worksheet

First binomial formula (a+b)2 =a 2+2 ab+b 2 https: //www. youtube. com/watch? v=k-d. Gzl. WNblo • (a+b) x (a+b) • axa + axb + bxa + bxb

Example: formula 1 (2 a+5 b)2 = (2 a+5 b)x(2 a+5 b) = 2 ax 2 a+2 ax 5 b+5 bx 2 a+5 bx 5 b = 4 a 2+10 ab+25 b 2 = 4 a 2+20 ab+25 b 2

Second binomial formula (a-b)2=a 2 -2 ab+b 2 The second formula is basically like the first one only with a minus instead of a plus. • (a-b)x(a-b) • axa - axb - bxa + bxb

Example: formula 2 (4 a-3 b)2 = (4 a-3 b)x(4 a-3 b) = 4 ax 4 a-4 ax 3 b-3 bx 4 a+3 bx 3 b = 16 a 2 -12 ab+9 b 2 = 16 a 2 -24 ab+9 b 2

Third binomial formula (a+b)x(a-b)= a 2 -b 2 https: //www. youtube. com/watch? v=Y-z-j. K 04 Va. I • a 2 -ab+ba-b 2 = a 2 -b 2

Example: formula 3 (8 a+1 b)x(8 a-1 b) = 8 a x 8 a - 8 a x 1 b + 1 b x 8 a - 1 b x 1 b = 64 a 2 - 8 ab + 8 ab - 1 b 2 = 64 a 2 - b 2

Why don`t you use BIDMAS? If you use BIDMAS to answer your question you would solve it in a different way, which would lead you to a wrong answer, so you can`t use BIDMAS! You also don`t use BIDMAS because there are letters and letters work in a different way in BIDMAS!

Quiz

1. (a+b) 2 = a) a + 2 ab + b b) a 2 + 2 ab + b 2 c) a 2 + 2 ab + 2 d) a 2 + 2 ab – b 2

2. Wich formulae is this (1)? a) 2 b) 1 c) 3 d) non of these obove.

3. Our theme is… a) …binominal formulae b) …binomial formulae c) …binomial formula d) …binominal formulas

Resources • http: //www. purplemath. com/modules/binomial. htm • https: //en. wikipedia. org/wiki/Binomial_theorem • Mathbook • https: //www. youtube. com/watch? v=k-d. Gzl. WNblo • https: //www. youtube. com/watch? v=Y-z-j. K 04 Va. I

Math presentation: Binomial formulae • First binomial formula: (a+b)2 =(a 2 + 2 ab+ b 2) • Second binomial formula: (a-b)2=a 2 -ab-ab+b 2 • Example: • • (2 a+5 b)2 • (4 a-3 b)2 • (4 a-3 b)x(4 a-3 b) • (2 a+5 b)x(2 a+5 b) • 4 ax 4 a-4 ax 3 b-3 bx 4 a+3 bx 3 b • 2 ax 2 a+2 ax 5 b+5 bx 2 a+5 bx 5 b • 16 a 2 -12 ab+9 b 2 • 4 a 2+10 ab+25 b 2 • 16 a 2 -24 ab+9 b 2 • 4 a 2+20 ab+25 b 2

• Third binomial formula: (a+b)x(a-b)= a 2+b 2 • Example: • (8 a+1 b)x(8 a-1 b) • 8 a x 8 a- 8 a x 1 b + 1 b x 8 a - 1 b x 1 b • 64 a 2 - 8 ab+ 8 ab - 1 b 2 • 64 a 2 - b 2 • Why we don‘t use BIDMAS • If you use BIDMAS to answer your question you would solve it in a different way, which would lead you to a wrong answer, so you can`t use BIDMAS! • You also don`t use BIDMAS because there are letters and letters work in a different way in BIDMAS!