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=+-7sqrt2

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+-sqrt37)/3}

500

3x^2+x=2x+7

x={(1+-sqrt85)/6}

Solve using the most efficient method.

100

x²=-6+7x

{6,1}

200

(x-2)²-8=-7

{3,1}

300

7x²+4x-8=0

-2+2sq.root(15)/7

-2-2sq.root(15)/7

400

4x²-81=0

{9/2, -9/2}

500

7x²-26x+9=-6

{5/7, 3}