5)
Aria dreptunghiului = L × l = 256 m²
( 3 x + 5 ) × 8 = 256
24 x + 40 = 256
24 x = 256 - 40
x = 216 : 24
x = 9
L = 3 × 9 + 5 = 27 + 5 = 32 m → lungimea
Perimetrul = 2 × L + 2 × l = 2 × 32 m + 2 × 8 m = 64 + 16 = 80 m
13) Notez cu x suma de bani
x + 4 % x = 936 ; 4 / 100 = 1 / 25
x + x / 25 = 936
25 x + x = 25 × 936
26 x = 25 × 936 l : 26
x = 25 × 36
x = 900 lei → suma depusa
