Question

数学 七年级 下册

(m+2n)(m-2n)=
(2n+5)(n-3)=
(x+2y)^2=
(ax+b)(cx+d)=
(x+y)(a+2b)=
(2a+3)(3/2b+5)=
(2x+3)(-x-1)=
(-2m-1)(3m-2)=
(x+y)^2=
(-2x+3)^2=
要过程。

Answer 1

1.m² - 2mn + 2mn - 4n² = m² - 4n²
2.2n² - 6n + 5n - 15 = 2n² - n -15
3.x² + 2xy + 2xy + 4y² = x² + 4xy + 4y²
4.acx² + adx + bcx + bd
5.ax + 2xb + ay + 2by
6.3ab + 10a + 9/2b +15
7.-2x² - 2x - 3x -3 = -2x² - 5x -3
8.-6m² + 4m - 3m + 2 = -6m² + m + 2
9. x² + xy + xy + y² = x² + 2xy + y²
10.(-2x+3)*(-2x+3) = 4x² - 6x - 6x + 9 = 4x² - 12x + 9

Answer 2

(m+2n)(m-2n)= m² - 2mn + 2mn - 4n² = m² - 4n²
(2n+5)(n-3)=2n² - 6n + 5n - 15 = 2n² - n -15
(x+2y)^2=(x+2y)*(x+2y) = x² + 2xy + 2xy + 4y² = x² + 4xy + 4y²
(ax+b)(cx+d)= acx² + adx + bcx + bd
(x+y)(a+2b)=ax + 2xb + ay + 2by
(2a+3)(3/2b+5)= 3ab + 10a + 9/2b +15
(2x+3)(-x-1)= -2x² - 2x - 3x -3 = -2x² - 5x -3
(-2m-1)(3m-2)= -6m² + 4m - 3m + 2 = -6m² + m + 2
(x+y)^2=(x+y)*(x+y) = x² + xy + xy + y² = x² + 2xy + y²
(-2x+3)^2=(-2x+3)*(-2x+3) = 4x² - 6x - 6x + 9 = 4x² - 12x + 9

Answer 3

m^2-4n^2
2n^2-n-15
x^2+4xy+4y^2
acx^2+bcx+adx+bd
ax+2bx+ay+2by
3ab+10a+9/2*b+15
-2x^2-5x-3
-6m^2+m+2
x^2+2xy+y^2
4x^2-12x+9

Answer 4

不、会、吧？！ 这个很简单的耶，你还是自己尝试做一下吧

Answer 5

(m+2n)(m-2n)=m^2-(2n)^2=m^2-4n^2 (平方差)
(2n+5)(n-3)=2n^2-6n+5n-15=2n^2-n-15
(x+2y)^2=x^2+4xy+4y^2
(ax+b)(cx+d)=acx^2+abx+bcx+bd=acx^2+b(a+c)x+bd
(x+y)(a+2b)=ax+2bx+ay+2by
(2a+3)(3/2b+5)=3ab+10a+9/2b+15
(2x+3)(-x-1)=-2x^2-2x-2x-3=-2x^2-4x-3
(-2m-1)(3m-2)=-6m^2+4m-3m+2=-6m^2+m+2
(x+y)^2=x^2+2xy+y^2
(-2x+3)^2=4x^2+12x+9

Answer 6

这个很简单啊，提公因式，平方差，完全平方式