Cogito
Algebra 2 · Chapter 5 · Lesson 2
Simplifying and Combining Radicals
Pull out the perfect squares, then collect like terms.
12 problems · about 21 minutes · N-RN.A.2, A-SSE.A.2
Figure — use these to answer the problems
- Point(4, 2)
Warm Up
Straightforward practice. Get the method working first.
5 problems√45 = a√5. What is a?
AnswerWhy can √2 + √3 not be combined?
- They are unlike radicals, the way 2x and 3y are unlike terms.
- The numbers are too small.
√18 = a√2. What is a?
Answer√75 = a√3. What is a?
Answer3√5 + 4√5 = a√5. What is a?
Answer
Build It Up
The same ideas with more to keep track of.
3 problems√2 × √8 equals what number?
Answer√(9 + 16) equals what?
Answer6 ÷ √3, rationalised, is a√3. What is a?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsWhich pairs are like radicals once simplified?
- √8 and √18
- √27 and √12
- √2 and √3
- √5 and √7
- Tick every box that applies.
(2 + √3)(2 − √3) equals what number?
AnswerThe Simplify
√12 simplifies to a√3. What is a?
AnswerThe Diagonal
A square has area 32. Its side is a√2. What is a?
Answer