IXL - Solve a quadratic equation using square roots (Precalculus practice)

Solve for

–

Write your answer in simplified, rationalized form.

ref_doc_title.

Learn with an example

question

Solve for

–

169

Write your answer in simplified, rationalized form.

key idea

	Solutions of x 2 = a
a > 0	Two real solutions: x = a and x = – a
a = 0	One real solution: x = 0
a < 0	Two imaginary solutions: x = 𝑖 absolute value bar a absolute value bar and x = – 𝑖 absolute value bar a absolute value bar

solution

To solve the equation

–

169

take the square root of both sides. Since

–

169

is negative, the solutions will be imaginary numbers.

Take the square root of both sides

–

169

Take the square root of both sides

Factor out 𝑖

𝑖

169

Factor out 𝑖

Simplify

13𝑖

Simplify

So, there are two imaginary solutions:

13𝑖

and

–

𝑖

Looking for more? Try this:

$Confetti$

Excellent!

Now entering the Challenge Zone—are you ready?

Questions
answeredQuestions

Time
elapsedTime

hr	min	sec
00	00	04

SmartScore
out of 100
IXL's SmartScore is a dynamic measure of progress towards mastery, rather than a percentage grade. It tracks your skill level as you tackle progressively more difficult questions. Consistently answer questions correctly to reach excellence (90), or conquer the Challenge Zone to achieve mastery (100)! Learn more

Teacher tools

Work it out

Not feeling ready yet? These can help:

K.1Introduction to complex numbers

EE.3Simplify radical expressions involving fractions

Excellent! You got that right!

Jumping to level 1 of 1

Excellent!