Question

acronyms for mande speakers

Answer 1

Answer:

formula (a+b+c) 2  =a2 +b 2 +c 2 +2(ab+ bc+ ca)

(3a-7b-c)2 =(3a)2 +(-7b)2 +(-c) 2 +2{(3a)(-7b) +(-7b)(-c) +(-c)(3a)}

=9a2+49b2+c2 -42ab+14bc-6ca