(2x+1)^3-(6x+2)(25x^2-10x+4)+(x-5)^3-(5+3x)^3 rút gọn 17/07/2021 Bởi Eliza (2x+1)^3-(6x+2)(25x^2-10x+4)+(x-5)^3-(5+3x)^3 rút gọn
Đáp án: $=-143x^3-138x^2-144x-761$ Giải thích các bước giải: $(2x+1)^3-(5x+2)(25x^2-10x+4)+(x-5)^3-(5+3x)^3$ $=[(2x)^3+3.(2x)^2.1+3.2x.1^2+1^3]-[(5x)^3+8^3]+(x^3-3.x^2.5+3.x.5^2-5^3)-[5^3+3.5^2.3x+3.5.(3x)^2+(3x)^3$ $=(8x^3+12x^2+6x+1)-(125x^3+512)+(x^3-15x^2+75x-125)-(125+225x+135x^2+27x^3)$ $=8x^3+12x^2+6x+1-125x^3-512+x^3-15x^2+75x-125-125-225x-135x^2-27x^3$ $=-143x^3-138x^2-144x-761$ Bình luận
Đáp án: $=-143x^3-138x^2-144x-761$
Giải thích các bước giải:
$(2x+1)^3-(5x+2)(25x^2-10x+4)+(x-5)^3-(5+3x)^3$
$=[(2x)^3+3.(2x)^2.1+3.2x.1^2+1^3]-[(5x)^3+8^3]+(x^3-3.x^2.5+3.x.5^2-5^3)-[5^3+3.5^2.3x+3.5.(3x)^2+(3x)^3$
$=(8x^3+12x^2+6x+1)-(125x^3+512)+(x^3-15x^2+75x-125)-(125+225x+135x^2+27x^3)$
$=8x^3+12x^2+6x+1-125x^3-512+x^3-15x^2+75x-125-125-225x-135x^2-27x^3$
$=-143x^3-138x^2-144x-761$