Question

Problemele 3,4,5! Va rog muult!! Dau coronita si 23 pcte.

Answer 1

3) 
a:15/2= (6,2+16,3):2
a:15/2 = 22,5 :2
a:15/2 = 225/10 *1/2
a:15/2 = 225/20
a=225/20 * 15/2 ⇒ a=225*15 :40=3375/40=84,375

4)
x*2/5=x-30
2x/5 = x-30
30=x-2x/5
30=5x/5-2x/5
30=3x/5
30*5=3x
150=3x
x=150:3
x=50