Sagot :
bsr
rappel de cours : k (a + b) = k * a + k * b
on applique
B = 8 * 3t + 8 * (-1) = 24t - 8
C = -5z * 2z - 5z * (-9) = -10z² + 45z
A = 3 * 4x + 3 * 2 = 12x + 6
et
D = -4x * 7 - 4x * (-3x) = ...
☺ Salut ☻
[tex]\rule{6cm}{1mm}[/tex]
[tex]A=3(4x+2)[/tex]
[tex]A=3\times 4x + 3\times 2[/tex]
[tex]\boxed{\red{A=12x+6}}[/tex]
[tex]\rule{6cm}{1mm}[/tex]
[tex]B=8(3t-1)[/tex]
[tex]B=8\times 3t + 8\times (-1)[/tex]
[tex]\boxed{\red{B=24t-8}}[/tex]
[tex]\rule{6cm}{1mm}[/tex]
[tex]C=-5z(2z-9)[/tex]
[tex]C=-5z\times 2z - 5z\times (-9)[/tex]
[tex]\boxed{\red{C=10z^{2}-45z}}[/tex]
[tex]\rule{6cm}{1mm}[/tex]
[tex]D=-4x(7-3x)[/tex]
[tex]D=-4x\times 7 - 4x\times (-3x)[/tex]
[tex]\boxed{\red{D=12x^{2}-28x}}[/tex]
[tex]\rule{6cm}{1mm}[/tex]