7 × m + 5 < 26 → inecuatie
7 × m < 26 - 5
7 × m < 21
m < 21 : 7
m < 3 ⇒ m = ( 0, 1, 2 )
Verific: 7 ×0 + 5 = 5 < 26
7 × 1 + 5 = 12 < 26
7 × 2 + 5 = 19 < 26
x-(43-11)=26
x - 32 = 26
x = 26 + 32
x = 58
Verific: 58 - 32 = 26
( 64 + 13 ) - x = 59
77 - x = 59
x = 77 - 59
x = 18