d) A = - 12x + 3x(4 - 2x) + 6x²
si x = - 3/7
A = - 12*-3/7 + 3*-3/7 (4 - 2*-3/7) + 6*(-3/7)²
A = 36/7 - 9/7(4 +6/7) + 6* 9/49
A = 36/7 -9/7 (4*7/7 + 6/7) + 54/49
A = 36/7 - 9/7 (28/7 + 6/7) + 54/49
A =36/7 - 9/7*34/7 + 54/49
A = 36/7 - 306/49 + 54/49
A = 36*7/7*7 - 306/49 + 54/49
A = 252/49 - 306/49 + 54/49
A = - 54/49 + 54/49
A = 0
si x = π
A = - 12x + 3x(4 - 2x) + 6x²
A = - 12*π + 3*π(4 - 2*π) + 6*π²
A = - 12π + 3π*4 - 3π*2π + 6π²
A = - 12π + 12π - 6π² + 6π²
A = 0
