calcule o valor de x nas equaçoes :
a) 4(x + 3) = 20
b) 5(2x - 1 ) = 2(x + 4 )
c) 10 - 2(x + 3 ) = 8 + 3(2x + 5 )
d) 3x/5 - 1/2 = x - 2/5
e) x/2 + 3/4 = 2x/6 - 1/3
Respostas
respondido por:
28
a) 4x+12=20 b) 10x-5=2x+8 c) 10 -2x -6= 8+ 6x+15 d) 6x-5=10x-4
4x=20-12 8x=13 10-15-6=6x+2x -5+4=10x-6x
4x=8 x=13/8 -11=8x -1=4x
x=2 -11/8=x -1/4=x
mmc {5,2}=10
e) 6x+3x=4x-4
9x=4x-4
9x-4x=-4
5x=-4
x=-4/5
mmc{2,3,4,6}=12
4x=20-12 8x=13 10-15-6=6x+2x -5+4=10x-6x
4x=8 x=13/8 -11=8x -1=4x
x=2 -11/8=x -1/4=x
mmc {5,2}=10
e) 6x+3x=4x-4
9x=4x-4
9x-4x=-4
5x=-4
x=-4/5
mmc{2,3,4,6}=12
respondido por:
27
Boa tarde,
a) 4(x + 3) = 20
4x+12=20
4x=20-12
4x=8
x=
x=2
b) 5(2x - 1 ) = 2(x + 4 )
10x-5=2x+8
10x-2x=8+5
8x=13
x=
x=1.625
c) 10 - 2(x + 3 ) = 8 + 3(2x + 5 )
10-2x-6= 8 +6x+15
-2x-6x=8+15-10+6
-8x=7
x=-=-0,875
d) 3x/5 - 1/2 = x - 2/5 mmc de 5,2=
5|2|2
5|1|5
1|1
-=-
mmc de 5 ,2 e 1=10
6x-5=10x-4
6x-10x=-4+5
-4x=-1
x=-=
x=0.25
e) x/2 + 3/4 = 2x/6 - 1/3 mmc de 2,4 ,6,3
2|4|6|3| 2
1|2|3|3| 2=12
1|1|3|3|3
1|1|1|1
(12:2)/12+(12:4.3)/12= (12:6.2x)/12-(12:3.1)/12
6/12+9/12=4x/12-4/12=
6x+9=4x-4
6x-4x=-4-9
2x=-13
x=-13/2=-6,5
a) 4(x + 3) = 20
4x+12=20
4x=20-12
4x=8
x=
x=2
b) 5(2x - 1 ) = 2(x + 4 )
10x-5=2x+8
10x-2x=8+5
8x=13
x=
x=1.625
c) 10 - 2(x + 3 ) = 8 + 3(2x + 5 )
10-2x-6= 8 +6x+15
-2x-6x=8+15-10+6
-8x=7
x=-=-0,875
d) 3x/5 - 1/2 = x - 2/5 mmc de 5,2=
5|2|2
5|1|5
1|1
-=-
mmc de 5 ,2 e 1=10
6x-5=10x-4
6x-10x=-4+5
-4x=-1
x=-=
x=0.25
e) x/2 + 3/4 = 2x/6 - 1/3 mmc de 2,4 ,6,3
2|4|6|3| 2
1|2|3|3| 2=12
1|1|3|3|3
1|1|1|1
(12:2)/12+(12:4.3)/12= (12:6.2x)/12-(12:3.1)/12
6/12+9/12=4x/12-4/12=
6x+9=4x-4
6x-4x=-4-9
2x=-13
x=-13/2=-6,5
Perguntas similares
7 anos atrás
7 anos atrás
7 anos atrás
9 anos atrás
9 anos atrás
9 anos atrás