bjr
a)( 6x +5) + (3x+4) = 6x + 5 + 3x + 4 = 9x + 9
b) (5x+4) - (2x-4) = 5x + 4 - 2x + 4 = 3x + 8
c) (-6x+7) - (-x+6) = -6x + 7 + x - 6 = -5x + 1
Développer et réduire les expressions suivantes
a) 6(x+6) =6x + 6*6 = 6x + 36
b) (2x+3)(4x+5) = 8x² + 10x + 12x + 15 = 8x² + 22x + 15
c) (2x-6)(3x-7) = 6x² - 14x - 18x + 42 = 6x² - 32x + 42
puisque k(a+b) = ka + kb
et que (a+b) (c+d) = ac + ad + bc + bc
Réponse :
Bonjour,
a) (6x + 5) + (3x + 4)
= 6x + 5 + 3x + 4
= 6x + 3x + 5 + 4
= 9x + 9
b) (5x + 4) - (2x - 4)
= 5x + 4 - 2x + 4
= 5x - 2x + 4 + 4
= 3x + 8
c) (-6x + 7) - (-x + 6)
= -6x + 7 + x - 6
= -6x + x + 7 - 6
= -5x + 1
Développer et réduire:
a) 6(x + 6)
= 6 × x + 6 × 6
= 6x + 36
b) (2x + 3)(4x + 5)
= 2x × 4x + 2x × 5 + 3 × 4x + 3 × 5
= 8x² + 10x + 12x + 15
= 8x² + 22x + 15
c) (2x - 6)(3x - 7)
= 2x × 3x - 2x × 7 - 6 × 3x + 6 × 7
= 6x² - 14x - 18x + 42
= 6x² - 32x + 42
