Resolver las siguientes ecuaciones de primer grado (cada ecuación correctamente resuelta equivale a 1 punto) A: 6 x + ( - x – 2 ) = ( 7 x – 3 ) – ( 8 – x ) B: x – ( 3 – x ) = 7 – ( x + 2 ) C: x – ( 1 – 3 x ) = 8 x – 1 D: 6 + 9 x – 15 + 21 x = - 2 x + 1 E: ( x + 30 ) + ( x + 25 ) = 7 x F: 4 x – 8 = - 4 ( 2 x – 3 ) + 4 G: 3 x – 5 = - 16 – x H: 1 – 6 x = 4 x – ( 3 – 2 x) I: 5 x – 5 ( 2 x + 1 ) = - 3 (4 x + 5 ) J: - 2 (3 x - 2) = - 2
Respuestas
Respuesta:
A: 6 x + ( - x – 2 ) = ( 7 x – 3 ) – ( 8 – x ) B: x – ( 3 – x ) = 7 – ( x + 2 ) C: x – ( 1 – 3 x ) = 8 x – 1 D: 6 + 9 x – 15 + 21 x = - 2 x + 1 E: ( x + 30 ) + ( x + 25 ) = 7 x F: 4 x – 8 = - 4 ( 2 x – 3 ) + 4 G: 3 x – 5 = - 16 – x H: 1 – 6 x = 4 x – ( 3 – 2 x) I: 5 x – 5 ( 2 x + 1 ) = - 3 (4 x + 5 ) J: - 2 (3 x - 2)
A: 6 x + ( - x – 2 ) = ( 7 x – 3 ) – ( 8 – x )
6 x - x - 2 = 7 x - 3 - 8 + x
5 x - 8 x = - 11 + 2
9 = 3 x
x = 3
B: x – ( 3 – x ) = 7 – ( x + 2 )
x-3+x=7-x-2
2x-3=5-x
2x+x=5+3
3x=8
x=8/3
C: x – ( 1 – 3 x ) = 8 x – 1
x-1+3x=8x-1
x+3x=8x
4x-8x=0
-4x=0
x=0
D: 6 + 9 x – 15 + 21 x = - 2 x + 1
-12x+2x=1+9
-10x=10
x=-1
E: ( x + 30 ) + ( x + 25 ) = 7 x
x + 30 + x + 25 = 7 x
2x+55=7x
2x-7x=-55
55=5x
x=11
F: 4 x – 8 = - 4 ( 2 x – 3 ) + 4
4 x - 8 = - 8 x + 12 + 4
4x -8 = -8x + 16
4x + 8x = 8 + 16
12 x = 24
x = 2
G: 3 x – 5 = - 16 – x
3x + x= - 16 + 5
4 x = - 11
x = -11/4
H: 1 – 6 x = 4 x – ( 3 – 2 x)
1 – 6 x = 4 x – 3 + 2 x
1 – 6 x = 6 x-3
– 6 x – 6 x = -3-1
- 12 x=-4
x=1/3
I: 5 x – 5 ( 2 x + 1 ) = - 3 (4 x + 5 )
5 x -10 x - 5 = -12 x+15
-5x -5 = -12x +1 5
-5x +12x = 15 + 5
7x = 20
x = 20/7
J: - 2 (3 x - 2) = - 2
3x -2 = 1
3x = 1 + 2
3x = 3
x = 1