1.(x+5)^2-(3-x)(3+x) 2.(2m-4)^2 3.(15+2c)^2 4.a^2-(3a-c)^2 - вопрос №511217515233224231522423252442 от роман507 04.06.2021 00:32

Question

Алгебра: 1.(x+5)^2-(3-x)(3+x) 2.(2m-4)^2 3.(15+2c)^2 4.a^2-(3a-c)^2 5.a^2+4ab+4b^2 6.4m^2-x^2

роман507 · Answer

1)(х+5)^2-(3-х)(3+х)=х^2+10х+25-9+х^2=2х^2+10х+16
2)(2m-4)^2=4m^2-16m+16
3)(15+2c)^2=225+60c+4c^2
4)a^2-(3a-c)^2=a^2-(9a^2-6ac+c^2)=a^2-9a^2+6ac-c^2=-8a^2+6ac-c^2
5)a^2+4ab+4b^2=(a+2b)^2
6)4m^2-x^2=(2m-x)(2x+x)