1. Solving Quadratic Equations by finding Square Roots
By: Destiny, Roberto, & Yaritza

2. Vocabulary A number “r” is a square root of a number “s” if r²=s.
A positive number “s” has two square roots denoted by √s and -√s
The symbol √ is a radical sign.
The expression √s is a radical.

3. Steps Equation: 2x²+1=17 1. write the original equation (2x²+1=17)
2. subtract 1 from each side (2x²=16)
3. divide each side by 2 (x²=8)
4. take square roots of each side (x=+or-√8)
5. simplify (x=√4√2 = 2√2)

4. Equation: 1/3(x+5)²=7
1. write the original equation (1/3(x+5)²=7)
2. multiple each side by 3 ((x+5)²=21)
3. take square roots of each side (x+5=√21)
4. subtract 5 from each side (x=√21-5)
5. simplify (-5 +or- √21)

5. Examples 5x²+7=47 -3(x+2)²=18 5x²=40 (x+2)²=-6 x=+or-√8 x=-2+or-i√6

6. Examples 1/5(x+8)²=13 2(x+7)²=48 (x+8)²=65 (x+7)²=24
x+8=+or-√ x+7=+or-√24
x=-8 +or-√ x=-7 +or-4√6