Expressions algébriques Ex1

Exercice 1

Développer et réduire chacune des expressions algébriques.

  1. $A = (4x + 3)(7x – 2) – 2x$
    $\quad$
  2. $B = (x+3)(2x – 1) + (x – 1)$
    $\quad$
  3. $C = x + 5(2x – 3) + 8(3 – 2x)$
    $\quad$
  4. $D = 2(2 + x) – 5(2x – 3)$

Correction

  1. $A = (4x + 3)(7x – 2) – 2x = 28x^2 – 8x + 21x – 6 – 2x  $ $= 28x^2 + 11x – 6$
    $\quad$
  2. $B = (x + 3)(2x – 1) + (x – 1) = 2x^2 – x + 6x – 3 + x – 1 $ $= 2x^2 + 6x – 4$
    $\quad$
  3. $C = x + 5(2x – 3) + 8(3 – 2x) = x + 10x – 15 + 24 – 16x $ $= -5x + 9$
    $\quad$
  4. $D = 2(2 + x) – 5(2x – 3) = 4 + 2x – 10x + 15 $ $= -8x + 19$