When m=0.5:
(3(0.5)-1)(0.5+2)-(0.5+3)(2(0.5)-1)
(1.5-1)(2.5)-(3.5)(1-1)
(0.5)(2.5)-0
0.625-0
= 0.625
When x=-0.5:
((-0.5)-2)(3(-0.5)+1)+(3(-0.5)-1)((-0.5)+2)
(-2.5)(-1.5)+(-1.5)(1.5)
3.75-2.25
= 1.5
When m=0.5:
(3(0.5)-1)(0.5+2)-(0.5+3)(2(0.5)-1)
(1.5-1)(2.5)-(3.5)(1-1)
(0.5)(2.5)-0
0.625-0
= 0.625
When x=-0.5:
((-0.5)-2)(3(-0.5)+1)+(3(-0.5)-1)((-0.5)+2)
(-2.5)(-1.5)+(-1.5)(1.5)
3.75-2.25
= 1.5