Question

[5x(5x-5)-120]x5-25=125​

Answer 1

Răspuns:  x = 7

Explicație pas cu pas:

• Metoda mersului invers

[ 5 × ( 5 × x - 5 ) - 120 ] × 5 - 25 = 125

[ 5 × ( 5 × x - 5 ) - 120 ] × 5 = 125 + 25

[ 5 × ( 5 × x - 5 ) - 120 ] × 5 = 150

5 × ( 5 × x - 5 ) - 120 = 150 : 5

5 × ( 5 × x - 5 ) - 120 = 30

5 × ( 5 × x - 5 ) = 30 + 120

5 × ( 5 × x - 5 ) = 150

5 × x - 5 = 150 : 5

5 × x - 5 = 30

5 × x = 30 + 5

5 × x = 35

x = 35 : 5

x = 7