Question

Sa se afle numarul natural x din relatiile a)5x+7=272 B)(8+3x)ori 14-30=1762
c)(72+x):25=17 D){[(3x+5)ori 3+5]ori 3+5}ori 3+5=281

Answer 1

a)
5×X+7=272
5×X=272-7
5×X=256
X=265:5
X=53

b)
(8×3×X)×14-30=1762
(8×3×X)×14=1762+30
(8×3×X)×14=1792
8×3×X=1792:14
8×3×X=128
3×X=128:8
3×X=16
X=16:3
X=5,3

c)
(72+X):25=17
72+X=17×25
72+X=425
X=425-72
X=353

d){[(3×X+5)×3+5]×3+5}×3+5=281
{[3×X+5)×3+5]×3+5}×3=281-5
{[(3×X+5)×3+5]×3+5}×3=276
[(3×X+5)×3+5]×3+5=276:3
[(3×X+5)×3+5]×3+5=92
[(3×X+5)×3+5]×3=92-5
(3×X+5)×3+5=87:3
(3×X+5)×3=29-5
3×X+5=24:3
3×X=8-5
X=3:3
X=1