Question

sa se rezolve binomul la putere (x-2y)^5 am nevoie la proba semestrială

Answer 1

Binomul lui Newton: $(a+b)^{n}=C_{n}^{0}*a^{n}+C_{n}^{1}*a^{n-1}*b+C_{n}^{2}a^{n-2}*b^{2} +...+C_{n}^{n}*b^{n}$

$(x-2y)^{5}=C_{5}^{0}*x^{5}+C_{5}^{1}*x^{5-1}*2y+C_{5}^{2}x^{5-2}*4y^{2}+C_{5}^{3}x^{5-3}*8y^{3}+ \\ \\ +C_{5}^{4}*16y^{4}+C_{5}^{5}*2^{5}*y^{5}$
$(x-2y)^{5}=x^{5}+5*x^{4}*2y+10x^{3}*4y^{2}+10 x^{2} 8y^{3}+5*16y^{4}+32y^{5}$