Question

Determina el valor de X en las siguientes ecuaciones de primer grado:

1) $6(2x-5)+2=20$

2) $5(3x-1)+3=13$

3) $9(7x-2)-10=36$

4) $12+3(2x-5)=9$

5) $25-5(4+3x)=15$

Answer 1

Despejando la variable " x " de cada ecuacion :

1)

6 ( 2x - 5 ) + 2 = 20
12x - 30 + 2 = 20
12x = 20 + 30 - 2
12x = 48
x = 48/12
x = 4                    → Solución

2 )

5 ( 3x - 1 ) + 3 = 13
15x - 5 + 3 = 13
15x = 13 + 5 - 3
15x = 15
x = 15/15
x = 1                     → Solución

3 )

9 ( 7x - 2 ) - 10 = 36
63x - 18 - 10 = 36
63x = 36 + 18 + 10
63x = 64
x = 64/63                    → Solución

4 )

12 + 3 ( 2x - 5 ) = 9
12 + 6x - 15 = 9
6x = 9 - 12 + 15
6x = 12
x = 12/6
x = 2                   → Solución

5 )

25 - 5 ( 4 + 3x ) = 15
25 - 20 - 15x = 15
5 - 15x = 15
- 15x = 15 - 5
- 15x = 10
x = 10/ -15
x = - 2/3            → Solución

Answer 2

6 (2x - 5) + 2 = 20
12x - 30 + 2 = 20
12x - 28 = 20
12x = 48
x = 48 / 12
x = 4

5 (3x - 1) + 3 = 13
15x - 5 + 3 = 13
15x - 2 = 13
15x = 15
x = 15 / 15
x = 1

9 (7x - 2) - 10 = 36
63x - 18 - 10 = 36
63x - 28 = 36
63x = 64
x = 64 / 63

12 + 3(2x-5) = 9
12 + 6x - 15 = 9
6x - 3 = 9
6x = 12
x = 12/6
x = 2

25 - 5(4+3x) = 15 
25 - 20 - 15x = 15
-15x + 5 = 15
-15x = 10
x = 10/- 15
x = - 2/3