Bereken met deze rekenregel: (a+b)(c+d) = ac+ad+bc+bd
(x+1)(y+4)
- 1x.4y
- xy+4x+y+4
- 4xy
- xy+4x.y+4
(x-4)(y+5)=
- xy-5y-4y+20
- xy+5y.4y-20
- xy-5y-4y-20
- xy+5x-4y-20
(x-6)(-y-7) =
- xy+7x-6y-42
- -xy-7x+6y+42
- -42xy
- xy-7x.6y+42
(x-12)(-a-3) =
- ax+3x-12a-36
- -ax-3x-12a-36
- -ax-3x+12a+36
- ax+3x+12a+36
(5-x)(-y-3)
- -5x.3y
- -5y-15+xy+3x
- 5y+15-xy-3x
- -5y-15-xy-3x
(-3+y)(2-x) =
- 3x-6-xy+2y
- -xy-2y+3x-6
- -6-3x.2y-xy
- -6+3x-2y-xy
(x-1)(2y-1) =
- 1-2xy-x+2y
- 2xy+x-2y-1
- 2xy-x-2y+1
- 1
(2x+5).(3y+9) =
- 6xy+18x+15y+45
- 18xy+6x+15y+45
- 6xy+18x.15y+45
- 24x²y+60y