Đáp án:
Giải thích các bước giải:
bài 3:
$1)(6x+1)^2+(6x-1)^2-2.(1+6x).(6x-1)$
$=36x^2+12x+1+36x^2-12x+1-2.(36x^2-1)$
$=72x^2+2-72x^2+2$
$=4$
$2)3.(2^2+1).(2^4+1).(2^8+1).(2^{16}+1)$
$=(2^2-1).(2^2+1).(2^4+1).(2^8+1).(2^{16}+1)$
$=(2^4-1).(2^4+1).(2^8+1).(2^{16}+1)$
$=(2^8-1).(2^8+1).(2^16+1)$
$=(2^{16}-1).(2^{16}+1)$
$=2^{32}-1$
$3)x.(2x^2-3)-x^2.(5x+1)+x^2$
$=2x^3-3x-5x^3-x^2+x^2$
$=-3x^3-3x$
$4)3x.(x-2)-5x.(1-x)-8.(x^2-3)$
$=3x^2-6x-5x+5x^2-8x^2+24$
$=-11x+24$
