1. SECTION 9-3 : SOLVING QUADRATIC EQUATIONS
ALGEBRA I @
SECTION 9-3 : SOLVING QUADRATIC EQUATIONS

2. How many x-intercepts, zero, one, or two, does each graph
have?
y = 3x y = 2x y = x2 – 6x
a) You will note at the x-intercept, y = 0. Let’s set each of these equations equal to zero and solve.
So, the x-intercept(s) and the solutions for each equation are the same.

3. The solutions to an equation are also called roots and zeros.

4. ALGEBRA I - SECTION 9-3 (Solving Quadratic Equations)
11/20/2018
2) Find the solutions to 3x2 – 75 = 0.
3x2 – 75 = 0
3x = 75 add 75 to both sides
x = 25 divide both sides by 3
take the square root of both sides
simplify
So, the solutions are 5 and -5.

5. Solve each equation by finding square roots
Solve each equation by finding square roots. If the equation has no real number solutions, write no solutions.
3) x2 – 16 = 0
ANSWER : 4 and -4
4) (x – 2)2 = 0
ANSWER : 2
5) x = 0
ANSWER : no solutions
6) 5x2 – 45 = 0
ANSWER : 3 and -3
7) 7x2 – 140 = 0
ANSWER :