Question

Determinati cifra X pentru care are loc 44X+4X4+X44=1221!!VA ROG SI NU FACETI POZA!

Answer 1

44X+4X4+X44=1221. Scriem numerele sub forma 400+40+X+400+X*10+4+X*100+40+4=1221. Astfel obtinem 888+111X=1221. 
111X=1221-888=333, deci X=3.
Sper sa iti fie de folos, succes!

Answer 2

44X+4X4+X44 = 1 221

descompunem fiecare termen al sumei astfel:

400+40+X+400+10X+4 +100X+40+4=1221

800+80+8 + 100X+11X = 1 221

888 + 111X = 1 221

111X = 1 221 - 888

111X = 333

X = 333 : 111

X = 3

Verificare:

443 + 434 + 344 = 1 221 (adevarat)