afla x din 3(x-15)÷4-33=63

3 × ( X - 15 ) : 4 - 33 = 63

3 × (X - 15 ) : 4 = 63 + 33

3 × ( x - 15 ) : 4 = 96

3 × ( x - 15 ) = 96 × 4

3 × ( x - 15 ) = 384

x - 15 = 384 : 3

x - 15 = 128

x = 128 + 15

x = 143 → numarul, aflat prin metoda mersului invers

________________________________________

3 × ( 143 - 15 ) : 4 - 33 = 63

= 3 × 128 : 4 - 33 =

= 384 : 4 - 33 =

= 96 - 33 =

= 63