Question

Помогите решить x(x-3)=28

Answer 1

х(х-3)=28

х²-3х-28=0

D=9+112=121

x1=(3+11)/2=14/2=7

x2=(3-11)/2=-8/2=-4

Answer 2

$x \times (x - 3) = 28 \\ {x}^{2} - 3x = 28 \\ {x}^{2} - x = 28 \div 3 \\ {x}^{2} = - 4 \\ {x}^{2} = 7$