ecuaciones cuadráticas

-x2+7x-10=0

-x2+4x-7=0

x2+x+1=0

x2+(7-x)2=25

x2–2x+1=0

x2–5x+6=0

2x2–7x+3=0

2x-3=1-2x+x2

7x2+21x-28=0

x2–4x+4=0

x=2

x= ∉ℝ

x=2

x1=1, x2=-4

x1=5, x2=2

x1=3, x2=2

x1=3, x2=1/2

x1=4, x2=3

x=1

x=∉ℝ