1. Bellwork: 2/19/18
1) Factor and solve: 3x2_7x-20=0
2) Solve by graphing: x2_10x+12=0
3) Factor: 6x3-13x2-5x

2. Bellwork: 2/20/18 Find each square root. Solve each equation.
5. –6x = –60 6.
7. 2x – 40 = 0 8. 5x = 3

3. Graph: y=x2-12x-13

5. Solving Quadratic Equations-Square Roots
We will...
 solve quadratic equations by using square 
roots.

8. Solve using square roots. Check your answer.
x2 = –49
x2 = 169
x2 = 0
x2 = 144
x2 = –16

9. If necessary, use inverse operations to isolate the squared part 
of a quadratic equation before taking the square root of both 
sides.

10. Solve using square roots.
x2 + 7 = 15
16x2 – 49 = 0
(x – 5)2 = 16
100x = 0

11. When solving quadratic equations by using square roots, you 
may need to find the square root of a number that is not a 
perfect square. In this case, the answer is an irrational number. 
You can approximate the solutions.

12. Solve. Round to the nearest hundredth.
x2 = 15
–3x = 0
0 = 90 – x2
2x2 – 64 = 0
x = 0

13. Ms. McDonald is building a retaining wall along one of the 
long sides of her rectangular garden. The garden is twice 
as long as it is wide. It also has an area of 578 square 
feet. What will be the length of the retaining wall?

14. 8) 6) 9) Solve by Square Roots: 1) Solve by Factoring: 5) 3) 7) 10)4) 1) 2) 5) 3)
Solve by Square Roots: 6) 7) 8) 9)
10)
11)
4(x-5)2+2=18

15. Quadratic Flip Book How to Solve Quadratic Functions Square Roots
Factoring
Graphing
Completing the Square
Quadratic Formula