Respuestas
Respuesta:
1.= 20
2.= 10
3.= 20
Explicación paso a paso:
1. 5x + 45 + x + 15 = 180
5x + x + 45 + 15 = 180
6x + 60 = 180
6x = 180 - 60 =120 LEYES DE SIGNOS
6x = 120 + + = +
x = 120/6 + - = -
x = 20 - - = +
- + = -
2. 5x - 20 + 7x + 80 = 180
5x + 7x + 20 - 80 = 180
12x + 60 = 180
12x = 180 - 60
12x = 120
x = 120/16
x = 10
3. -2x + 90 + 8x -30 = 180
-2 +8 + 90 - 30 = 180
6X + 60 = 180 - 60
6x = 120
x = 120/6
x = 20