does anybody not understand the importance of knowing (a+b)(a-b)?

Question

why because it can be used to make multiplying easy

29*71
because (a+b)(a-b)=a^2-b^2

29*71=50^2-21^2
50^2=2500 (5^2=25 bung a couple of noughts at the end)
and 21^2=(20*22)+1 (the reverse) (2*22=44---add a zero)
therefore 29*71=2500-441=2059

want to know more ask me

also 22 rule

know all the squares up to 25
and multiplying becomes real easy trust me (ok so i am number freak)

why ask me

Answer 1

My twin brother and I memorized all the decimal fractions to 1/20 so we can do percentages faster.

I agree. Math is important to learn.