Quadratic Formula problems - please help?

Question

1) x^2 + 5x - 1 = 0

2) x^2 + 10x = 9 [Turn into a ( = 0 ) equation]

Answer 1

Remember that A^2 + Bx + C = 0.

In the first equation, A = 1, B = 5, and C = -1.  

Simply plug these values into the quadratic formula (see my source below).

For the second equation, subtract 9 from both sides to put it into A^2 + Bx + C = 0 format.  So, x^2 + 10x - 9 = 0.

A = 1, B = 10, and C = -9.

Now you have all of the tools!  Good luck.  :-)

Answer 2

A^2 + B +C

___ + ___ (change sign after equation) = AC

                (             therefore            )

x = -___

and

x = -___

Answer 3

The Quadratic Equation

ax^2 + bx + c = 0

The Quadratic Formula

x = {-b +- sqrt( b^2 - 4ac)} devide by 2a

where:

1) a = 1,  b = 5, c = -1

    

     Ans:

    (+)x = 0.19

    (-)x = -5.19

2) x^2 + 10x - 9 = 0

    

     a = 1,  b = 10, c = -9

     Ans:

    (+)x = 0.83

    (-)x =  -10.83

Answer 4

ax²+bx+c=0

use the quadratic formula

x= -b±√b²-4ac / 2a

in the 1st equation

1) x^2 + 5x - 1 = 0

a=1 b=5 c=-1

apply the formula and substitute the values

x= -5±√5²-4(1)(-1) / 2(1)

x= 5±√25+4 / 2

x= 5±√29 / 2

answer is 5 plus or minus the square root of 29 all over 2

2) x^2 + 10x = 9 [Turn into a ( = 0 ) equation]

first change it to zero equation

so.... x²+10x-9=0

a= 1  b= 10 c= -9

then apply the formula

x= -b±√b²-4ac / 2a

x= -10±√10²-4(1)(-9) / 2(1)

x= -10±√100+36 / 2

x= -10±√136 / 2

x= -5±√136

simplify: √136 =  Ã¢ÂˆÂš(4)(34) =2√34

x= -5±√(4)(34)

x=-5±2√34



the answer is -5 plus or minus 2 square root of 34

HOPE its helps....

gudluck... :P