SO SÁNH TÍNH CHẤT CƠ HỌC , TÍNH CHẤT CÔNG NGHỆ CỦA KIM LOẠI VÀ PHI KIM LOẠI ?

1.B

2.B

3.D

4.C

5.A

CHÚC BẠN TTHI TỐT

a) Ta có: x^4-6x^3+9x^2x4−6x3+9x2

=x^2\left(x^2-6x+9\right)=x2(x2−6x+9)

=x^2\cdot\left(x-3\right)^2=x2⋅(x−3)2

b) Ta có: x^3-1-\left(1-x\right)\left(x-5\right)x3−1−(1−x)(x−5)

=\left(x-1\right)\left(x^2+x+1\right)+\left(x-1\right)\left(x-5\right)=(x−1)(x2+x+1)+(x−1)(x−5)

=\left(x-1\right)\left(x^2+x+1+x-5\right)=(x−1)(x2+x+1+x−5)

=\left(x-1\right)\left(x^2+2x-4\right)=(x−1)(x2+2x−4)

c) Ta có: 36m^2-x^2+2xy-y^236m2−x2+2xy−y2

=36m^2-\left(x^2-2xy+y^2\right)=36m2−(x2−2xy+y2)

=\left(6m\right)^2-\left(x-y\right)^2=(6m)2−(x−y)2

=\left(6m-x+y\right)\left(6m+x-y\right)=(6m−x+y)(6m+x−y)

d) Ta có: 4a^2-9b^2+2xa-3bx4a2−9b2+2xa−3bx

=\left(2a-3b\right)\left(2a+3b\right)+x\left(2a-3b\right)=(2a−3b)(2a+3b)+x(2a−3b)

=\left(2a-3b\right)\left(2a+3b+x\right)=(2a−3b)(2a+3b+x)

chúc bạn thi tốt

Q=ab+a+1a​+bc+b+1b​+ac+c+1c​

Q=\dfrac{ac}{c\left(ab+a+1\right)}+\dfrac{abc}{ac\left(bc+b+1\right)}+\dfrac{c}{ac+c+1}Q=c(ab+a+1)ac​+ac(bc+b+1)abc​+ac+c+1c​

Q=\dfrac{ac}{abc+ac+c}+\dfrac{abc}{abc^2+abc+ac}+\dfrac{c}{ac+c+1}Q=abc+ac+cac​+abc2+abc+acabc​+ac+c+1c​

Q=\dfrac{ac}{1+ac+c}+\dfrac{1}{c+a+ac}+\dfrac{c}{ac+c+1}Q=1+ac+cac​+c+a+ac1​+ac+c+1c​

Q=\dfrac{ac+1+c}{1+ac+c}=1Q=1+ac+cac+1+c​=1

chúc bạn thi tốt

x^2-x-6 = x^2-3x+2x-6=(x^2-3x)+(2x-6)

=x(x-3)+2(x-3)

=(x-3)(x+2)