A = (7/3*6x + 7/3*3) + (5/2*4-2x*5/2)
= (42/3x + 7) + (5*2 - 5x)
= 14x+7+10-5x
= 9x +17
B = (4x+7)^2
= 16x^2 + 56x+49
C = (1.4x-1)^2
= 1.96x^2 - 2.8x +1
D = (2.1x-3)(2.1x+3)
= 4.41x - 9
E = (4t +1)(4t-1) -(3t+2)^2
= (16t^2-1)- (9t^2+12t+4)
= 16t^2 -1 -9t^2 -12t -4
= 17t^2 -12t -5