1)a. (3x-4)(x + 2)=3x²+6x+-4x-8=3x²+2x-8
1)b. B =(5x + 1)(3x-4)(x +2) = (5x+1)(3x²+2x-8)=15x^3+10x²-40x+3x²+2x-8
=> B = 15x^3+13x²-38x-8
2)a. x=1 => B =(5x + 1)(3x-4)(x +2) = (5+1)(3-4)(1+2)=6*(-1)*3=-18
2)b. x=1 => B = 15x^3+13x²-38x-8=(15*1)+(13*1)-(38*1)-8
=>B=15+13-38-8=-18