Expression A Calculer Ai Je Bon ?

[minnellea]

bonjour,

la suite des expressions a calculer en rempaçant par une lettre !

est ce que j'ai bon ?SVP

1° a= -2 ;b= 3;c=-1;d=0 x=1;y=0

2° a=1/2 ;b=-1/3;c=1/5 ;d=1/4;x=3;y=2

d) 3- (5-4x) -3-4+(7x -3)

= 3-5+4x -3-4 +7x-3

=11x-12

1)

11x-12

=11(1)-12

=1

2°

11x-12

=11(3)-12

=21

e) 2(5x-2) +4x -2(7x+1)

=10x-4 +4x+ (-2*7x)+(-2*1)

=-6 (impossible)

F)(4-7x) + (5-3x)-3(3x-5)-(x-6)-5+3x

= 4-7x +5 -3x - 9x+15 - x+6 -5+3x

= -17x+25

1)

-17x+25= -17(1)+25

=8

2) -17x+25= -17(3)+25

= -26

g)

2(x-1) -(7+2x) -(2x -2) +3(x-1)

=2x-1 -7+2x-2x-2+3x-1

=X-11

x-11= (1)-11=10

x-11=(3)-11=8

h)

[ (2a-(b-c)] -[-5a-(b-3c)] -[6a-(b+3c)]

2a-b+c-(-5a-b+3c)-(6a-b-3c)

=2a-b+c+5a+b-3c-6a+b+3c

=-a+b+c

a+b+c= -2+3+ -1=0

a+b+c= 1/2+(-1/3)+1/5=11/30

i)[(a-b)-(c+d)]-[a-d-(c+b)]-b+a

=

J) j=(2(ab+ac)-3a) -2((a+8)+c)

=2(ab+ac)-3a -2(a+8)-2ac

=2ab+2ac-3a -2a-16-2ac

=2ab-5a -16

2ab-5a-16 = 2(-2*3)-5(-2)-16= -12-+10-16=-18

2ab-5a-16= 2(1/2*-1/3)-5(1/2)-16= -1/3-5/2-16= -113/6

merci d'avance !

[Barbidoux]

bonjour,

la suite des expressions a calculer en rempaçant par une lettre !

est ce que j'ai bon ?SVP

1° a= -2 ;b= 3;c=-1;d=0 x=1;y=0

2° a=1/2 ;b=-1/3;c=1/5 ;d=1/4;x=3;y=2

d) 3- (5-4x) -3-4+(7x -3)

= 3-5+4x -3-4 +7x-3

=11x-12

1)

11x-12

=11(1)-12

=-1

2°

11x-12

=11(3)-12

=21

e) 2(5x-2) +4x -2(7x+1)

=10x-4 +4x+ (-2*7x)+(-2*1)

=-6 (impossible)

F)(4-7x) + (5-3x)-3(3x-5)-(x-6)-5+3x

= 4-7x +5 -3x - 9x+15 - x+6 -5+3x

= -17x+25

1)

-17x+25= -17(1)+25

=8

2) -17x+25= -17(3)+25

= -26

g)

2(x-1) -(7+2x) -(2x -2) +3(x-1)

=2x-1 -7+2x-2x-2+3x-1

=x-10

x-10= (1)-10=-9

x-10=(3)-10=-7

h)

[ (2a-(b-c)] -[-5a-(b-3c)] -[6a-(b+3c)]

2a-b+c-(-5a-b+3c)-(6a-b-3c)

=2a-b+c+5a+b-3c-6a+b+3c

= a+b+c

a+b+c= -2+3+ -1=0

a+b+c= 1/2+(-1/3)+1/5=11/30

i)[(a-b)-(c+d)]-[a-d-(c+b)]-b+a

= a-b

J) j=(2(ab+ac)-3a) -2((a+8)+c)

=2(ab+ac)-3a -2(a+8)-2ac-2c

=2ab+2ac-3a -2a-16-2ac-2c

= 2ab+2*ac-2 c-5a -16

=-12

-571/30