Question

Aflati valoarea lui x:                  1)     5(x+17)=125                     2)   148 - (2x +5)=3

Answer 1

5(x+17)=125
5x+85=125
5x=125-85
5x=40
x=40/5
x=8

148 - (2x +5)=3
148-2x-5=3
148-5-3=2x
140=2x
x=140/2
x=70

Answer 2

1)
5 (x + 17) = 125
5x + 85 = 125
5x = 125 - 85
5x = 40
x = 40/5
x = 8

2)
148 - (2x + 5) = 3

simplificam: 148 + -1*(2x + 5) = 3

 reordonam termenii:
148 + -1*(5 + 2x) = 3
148 + (5 * -1 + 2x * -1) = 3
148 + (-5 + -2x) = 3

 combinam termenii:
148 + -5 = 143
143 + -2x = 3
 
rezolvam: 143 + -2x = 3

 mutam termenii cu ,,x'' la stanga, restul la dreapta si adaugam -143 de fiecare parte a ecuatie:
143 + -143 + -2x = 3 + -143
 
combinam termenii:
143 + -143 = 0
0 + -2x = 3 + -143
 -2x = 3 + -143
  3 + -143 = -140 -2x = -140
 
dividem fiecare parte cu -2 si rezulta:  x = 70