C des mathématiques je suis en seconde aidez moi svp c un devoir maison

bonjour

A = ( 1 + 3/4 ) x 2/3 - 1 /3

A =  7/4 * 2/3 - 1/3

A = 14/12 - 1/3

A = 14/12 - 4 /12

=  10/12 = 5 /6

B  = ( 1/2 - 1/3 ) : ( 3/7 + 5/21 )

= ( 3/6 - 2 /6 ) ; ( 9/21 + 5 /21 )

= 1/6 : 14/21

= 1 /6 * 21/14

= 21/ 84

= 1/4

C  = 5.24 * 10² * 10 ⁻⁶ = 5.24 * 10 ⁻⁴

D = 45 * 10 ¹³ = 4.5 * 10 * 10 ¹³ = 4.5 * 10 ¹⁴

A = 5 x - 6 x - 3

= - x - 3

B = 20 x + 10  - 3 x² + 3

= - 3 x² + 20 x + 13

C = 4 x + 3 x - 2 x² + 3 - 2 x

= - 2 x² + 5 x + 3

D =  2 x ( 2 x - 3 )

E = ( x + 1 ) ( 2 x - 3 + 3 x )

= ( x + 1 ) ( 5 x - 3 )