Question

Which of the following equations has only one solution?
x2 + 4x + 4 = 0
x2 + x = 0
x2 - 1 = 0

Answer 1

Answer:

x^2+4x+4=0

Factor it (x+2)^2=0

One solution only x=-2

x^2+x=0

Factor it  x(x+1)=0

solutions are x=0,-1

x^2-1=0

Add 1 to both sides

x^2=1

Solutions are x=-1, 1

A quadratic equation only has one solution if the discriminant is zero.

Hope it helps

Answer 2

x²+4x+4=0

then (x+2)²=O

x+2=0

x=-2

x²+x=0

x(x+1)=0

x=0 or x=-1

x²-1=0

x²=1

x=±1

so the first ome