Question

(2-a)(3+a)-(2-a)(2+a)

(2-a)(3+a)-(2-a)(2+a)
(2x-5y)(2x+5y)-(4x+y)^2
(x-2y)(x-2y-3)-x(x+4y-3)

Answer 1

1.(2-a)(3+a)-(2-a)(2+a)
=(2-a)(3+a-2-a)
=(2-a)(1)
=2-a

2.(2x-5y)(2x+5y)-(4x+y)^2
=(4x^2-25y^2)-(16x^2+y^2+8xy)
=-12x^2-26y^2-8xy

3.(x-2y)(x-2y-3)-x(x+4y-3)
=(x-2y)(x-2y-3)-(x^2+4xy-3x)
=(x-2y)^2-3(x-2y)-(x^2+4xy-3x)
=x^2+4y^2-4xy-3x+6y-x^2-4xy+3x
=4y^2-8xy+6y

Answer 2

(2-a)(3+a)-(2-a)(2+a)
=(2-a)[(3+a)-(2+a)]
=(2-a)(3+a-2-a)
=2-a

(2x-5y)(2x+5y)-(4x+y)^2
=4x^2-25y^2-16x^2-8xy-y^2
=-12x^2-8xy-26y^2

(x-2y)(x-2y-3)-x(x+4y-3)
=(x-2y)^2-3(x-2y)-x^2-4xy+3x
=x^2-4xy+4y^2-3x+6xy-x^2-4xy+3x
=4y^2-2xy

Answer 3

(2-a)(3+a)-(2-a)(2+a)
=(2-a)(3+a-2-a)=2-a

(2x-5y)(2x+5y)-(4x+y)^2
=4x^2-25y^2-(16x^2+y^2+8xy)
=-24y^2-8xy

(x-2y)(x-2y-3)-x(x+4y-3)
=(x^2-2xy-3x-2xy+4y^2+6y)-x^2-4xy+3x
=(x^2-4xy-3x+6y)-x^2-4xy+3x
=-8xy+6y

Answer 4

(2-a)(3+a)-(2-a)(2+a)
=(6-a-a^2)-(4-a^2)
=2-a
(2x-5y)(2x+5y)-(4x+y)^2
=(4x^2-25y^2)-(16x^2+8xy+y^2)
=-12x^2-8xy-26y^2
(x-2y)(x-2y-3)-x(x+4y-3)
=(x-3)(x-2y)-2y(x-2y)-x(x-3)-4xy
=-2y(x-3)-2y(x-2y)-4xy
=-8xy+y+4y^2

Answer 5

(2-a)(3+a)-(2-a)(2+a)
=6+2a-3a-a^2-(4-a^2)
=6-a-a^2-4+a^2
=2-a

原式=4x^2-25y^2-16x^2-8xy-y^2
=-12x^2-8xy-26y^2

原式=(x-2y)^2-3(x-2y)-x^2-4xy+3y
=x^2-4xy+4y^2-3x+6y-x^2-4xy+3y
=-8xy+4y^2-3x+9y

Answer 6

原式=6+2a-3a-a^2-(4-a^2)
=6-a-a^2-4+a^2
=2-a

原式=4x^2-25y^2-16x^2-8xy-y^2
=-12x^2-8xy-26y^2

原式=(x-2y)^2-3(x-2y)-x^2-4xy+3y
=x^2-4xy+4y^2-3x+6y-x^2-4xy+3y
=-4xy+4y^2-3x+9y-4xy
=-8xy+4y^2-3x+9y