rozwiązanie
a)
(5x-7y)^2=(5x)^2-2*5x*7y+(7y)^2=25x^2-70xy+49y^2
b)
(3a+3b)^2=(3a)^2+2*3a*3b+(3b)^2=9a^2+18ab+9b^2
c)
(2a-3)(2a+3)=(2a)^2-3^2=4a^2-9
d)
(0,5a+4b)^2=0,25a^2+2*0,5a*4b+16b^2=0,25a^2+4ab+16b^2
e)
(2a-3b)^2=4a^2-12ab+9b^2
f)
(x^2-3)^2=x^4-6x^2+9