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

(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 2

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