Răspunsuri

2014-08-07T13:17:35+03:00
A:5=a-80

a=5(a-80)

a=5a -400

a-5a = -400

-4a = -400

4a=400  =>a=100
2 4 2
2014-08-07T13:23:33+03:00
X / 5 = x -80  aducem la acelasi numitor
x = 5x - 400
- 4x = - 400
x = 400 / 4
x = 100
verificare: 100 / 5 = 20 si 100 - 80 = 20