Question

When a=1,b= -2,then find value2a'b+2ab'2+3ab

Answer 1

2(1)(-2) + 2(1)(-2)2 + 3(1)(-2)
(-4) + (-8) + (-6)
(-18)

Answer 2

2(1)'(-2) + 2(1)(-2)'2 + 3(1)(-2)
2(-2)  + (-4)'2 + (-6)
1/2 +16 +(-6) 
1/2 + 10
21/2