Question

x(x+1)=3x+8 me ajudemmmm

Answer 1

x(x+1)=3x+8
x^2+x=3x+8
x^2+x-3x-8=0
x^2-2x-8=0

△= b^2-4ac
△= (-2)^2-4.1.(-8)
△= 4+32
△= 36

X= -b+/-√△%2a
X= -(-2)+/-√36%2.1
X= 2+/-6%2
X'= 2+6%2 ➡ X'= 4
X''= 2-6%2➡ X''= -2

S={-2,4}