Solving Quadratics ~ All Methods

Factoring

100

x^2-10x+21=0

x={3,7}

200

9x^2-25=0

x={-5/3,5/3}

300

3x^2-13x-30=0

x={-5/3,6}

400

3x^2=81-x^2

x={-9/2,9/2}

500

2x^2=x+21

x={-3,7/2}

Square Roots

100

5x^2-11=234

x=+-7

200

When is it best to use the square root method for solving quadratics?

When there is no 'b' term.

300

x^2-1=39

x=+-2sqrt10

400

4x^2-39=10

x=+-7/2

500

-2x^2-196=0

x=+-7isqrt2

Complete the Square

100

x^2-18x+56=0

x={4,14}

200

2x^2-16x=-30

x={3,5}

300

When is it best to use "complete the square" method for solving a quadratic equations?

When the 'b' term is even.

400

3x^2=3-42x

x={-7+-5sqrt2}

500

2x^2-20x+89=-87

x={5+-3isqrt7}

Quadratic Formula

100

When can you use this method to solve a quadratic equation?

ALWAYS 

200

-2x^2+3x=4x-15

x={-3,5/2}

300

x^2-9=4x

x={2+-sqrt13}

400

-3x^2+8x-7=0

x={(4+-isqrt5)/3}

500

3x^2+x=-2x-7

x={-1/2+-(5isqrt3)/6}