Question

The square of a negative number is twelve more than four times the negative number. Find the number.

Answer 1

x - the number


`x^2=4x+12 \\ x^2-4x-12=0 \\ x^2-6x+2x-12=0 \\ x(x-6)+2(x-6)=0 \\ (x+2)(x-6)=0 \\ x+2=0 \ \lor \ x-6=0 \\ x=-2 \ \lor \ x=6`

The number is negative, so x=-2.

The number is -2.