Question

ex 2 și 5.. Multumesc

Answer 1

132 : x = a rest 12 ==> xa = 132 -12 = 120
160 : x = b rest 10 ==>bx = 160-10 = 150
230 : x =c rest 20 ==>cx = 230-20 = 210

120 = 2^3×3×5
150 = 2×3×5^2
210 = 2 × 3 × 5 × 7
-----------------------------
c.m.m.d.c = 2×3×5 = 30

x = 30 (numarul caurat)


Verificam:
132 : 30 = 4 rest 12
160 : 30 = 5 rest 10
230 : 30 = 7 rest 20

5)
notam:
e = numarul elevilor
b = numarul bancilor

e = 2×b+3
e = 3×(b-3)

egalam cele doua relatii:
3×(b-3) = 2×b+3
3b - 9 = 2b + 3
3b - 2b = 3+9
b = 12 (banci)

e = 2×12+3 = 24+3 = 27 (elevi)