How do you factor the trinomial 2x^2+10x+25?

1 Answer
Dec 17, 2017

x=(-5+5i)/2,(-5-5i)/2

Explanation:

2x^2+10x+25 is a quadratic equation in standard form:

ax^2+bx+c,

where:

a=2, b=10, and c=25

Set the equation to 0 and solve for x.

0=2x^2+10x+25

Use the quadratic formula:

x=(-b+-sqrt(b^2-4ac))/(2a)

Plug in the known values.

x=(-10+-sqrt(10^2-4*2*25))/(2*2)

Simplify.

x=(-10+-sqrt(-100))/4

Prime factorize the square root.

x=(-10+-sqrt(-2xx2xx5xx5))/4

Simplify.

x=(-10+-10i)/4

Factor out the common 2 in the numerator.

x=(2(-5+-5i))/4.

Divide 4 in the denominator by the 2 in the numerator.

x=(-5+-5i)/2

Solutions for x.

x=(-5+5i)/2,(-5-5i)/2