Jawabanmu

2014-08-25T01:00:25+07:00
1.(7x+2y)(4x-3y)=28x^2-21xy+8xy-6y^2=28x^2-13xy+6y^2
2.(1/2 x+y)(y-1/2)=1/2xy-2/4+y^2-1/2y
3.(3x+1)(3x-1)=9x^2-3x+3x-1=9x^2-1