Question

номер 4) 5+...помогите плиз

Answer 1

$5+ frac{7y-12}{3}=y+13\\ frac{7y-12}{3}-y=13-5\\ frac{7y-12-3y}{3}=8 \\ 4y-12=8cdot3\\ 4y=24+12\\ 4y=36\\ y=36:4\\ y=9$