Question

ecuaciones de primer grado con una incógnita
1.) 2 x-7 = -3
2.) 3x + 5 = -1
3.) 2x - 8 = 10
4.) 5x - 7 + 2x = 4x + 5
5.) 5x -2x - 4 = x + 7 - 5
6.) x - ( 2x + 1 ) = 8 - (3x + 3 )
7.) 2 ( x - 1 ) - 5 = 14 - x
8.) 15x - 10 = 6x - ( x - 2 ) + ( - x + 3 )
9.) x + 3 ( x + 1 ) = 6 - 4 ( 2x + 3 )

Answer 1

1)

$2x - 7 = - 3 \\ 2x = - 3 + 7 \\ 2x = 4 \\ x = 4 \div 2 \\ x = 2$

2)

$3x + 5 = - 1 \\ 3x = - 1 - 5 \\ 3x = - 6 \\ x = - 6 \div 3 \\ x = - 2$

3)

$2x - 8 = 10 \\ 2x = 10 + 8 \\ 2x = 18 \\ x = 18 \div 2 \\ x = 9$

4)

$5x - 7 + 2x = 4x + 5 \\ 7x - 7 = 4x + 5 \\ 7x - 4x = 5 + 7 \\ 3x = 12 \\ x = 12 \div 3 \\ x = 4$

5)

$5x - 2x - 4 = x + 7 - 5 \\ 3x - 4 = x + 2 \\ 3x - x = 2 + 4 \\ 2x = 6 \\ x = 6 \div 2 \\ x = 3$

6)

$x - (2x + 1) = 8 - (3x + 3) \\ x - 2x - 1 = 8 - 3x - 3 \\ - x - 1 = - 3x + 5 \\ - x + 3x = 5 + 1 \\ 2x = 6 \\ x = 6 \div 2 \\ x = 3$

7)

$2(x - 1) - 5 = 14 - x \\ 2x - 2 - 5 = 14 - x \\ 2x - 7 = 14 - x \\ 2x + x = 14 + 7 \\ 3x = 21 \\ x = 21 \div 3 \\ x = 7$

8)

$15x - 10 = 6x - (x - 2) + ( - x + 3) \\ 15x - 10 = 6x - x + 2 - x + 3 \\ 15x - 10 = 4x + 5 \\ 15x - 4x = 5 + 10 \\ 11x = 15 \\ x = 15 \div 11 \\ \frac{15}{11}$

9)

$x + 3(x + 1) = 6 - 4(2x + 3) \\ x + 3x + 3 = 6 - 8x - 12 \\ 4x + 3 = - 8x - 6 \\ 4x + 8x = - 6 - 3 \\ 12x = - 9 \\ x = - 9 \div 12 \\ x = - \frac{9}{12} \\ x = - \frac{3}{4}$