Question

(x+15)(x+5)=-9 буде добры помогите

Answer 1

$(x+15)(x+5) = -9\ x^2 + 20x+75 = -9\ x^2+20x+84 = 0 \ (x+14)(x+6) = 0\ left [ {x=-14} atop {x=-6}} right.$

x=-14 или x=-6