Question

Afla termenul necunoscut din urmatoarele egalitatii:
a) [(4•m+5):3+10]:5+5=10 ???
b) [(13+12•m)•10-330]:100=13 ????

Answer 1

a) [(4m + 5) : 3 + 10] : 5 + 5 = 10 
= [(4m + 5) : 3 + 10] : 5 = 10 - 5 = 5
= (4m + 5) : 3 + 10 = 5 · 5 = 25
= (4m + 5) : 3 = 25 - 10 = 15
= 4m + 5 = 15 · 3 = 45
= 4m = 45 - 5 = 40 ⇒ m = 40 : 4 = 10.

b) [(13 + 12m) · 10 - 330] : 100 = 13
= (13 + 12m) · 10 - 330 = 13 · 100 = 1300
= (13 + 12m) · 10 = 330 + 1300 = 1630
= 13 + 12m = 1630 : 10 = 163
= 12m = 163 - 13 = 150 ⇒ m = 150 : 12 = 12,5.

/robertinni