Răspuns:
Explicație pas cu pas:
a) 5(x+3)+2x[2+3(x+2)]=31
5x + 15 + 2× (2+3x+6) = 31
5x + 15 + 2×(3x+8) = 31
5x + 15 + 6x + 16 = 31
11x + 31 = 31
11x = 31 - 31
11x = 0
x = 0