Question

решите уравнение: x²-5×(6-x)=-30

Answer 1

X2-5×(6-x)=-30

X2-30+5=-30

X2+5=0

X×(x+5)=0

X=0

X+5=0

X1=0

X2=-5

Answer 2

почему 5,

Answer 3

${x}^{2} - 30 + 5x = - 30$
${x}^{2} + 5x = - 30 + 30$
${x}^{2} + 5x = 0$
$d = {b}^{2} - 4ac = 25$
$x1 = frac{b + sqrt{d} }{2a} = frac{ - 5 + 5}{2} = - 5$
$x2 = frac{b - sqrt{d} }{2a} = frac{ - 5 - 5}{2} = 0$