ok... I understood the last part, but now I get it negative instead of positive. Please help!!!!?

Question

ok...

I have x^2 + 6x - 7 = 0

and

x = -b+/- √(b^2 - 4ac) / 2a

I get x1=7 and x2 = -1

but the book says -7 and 1

I get it negative and it says possitive

Answer 1

(-b +/- sqrt (b^2-4ac))/2a

= (-6 +/- sqrt (36-4*1*-7))/2
= (-6 +/- sqrt (36+28))/2
= (-6 +/- sqrt (64))/2
= (-6 +/- 8)/2
= 2/2 or -14/2

or 1 or -7

Answer 2

Book is correct; by inspection, the factors are (x+1)(x-7). The quantity under the radical is 64; the square root is 8, so you get (-6+8)/2 and (-6-8)/2, which are 1 and -7, respectively. Watch those signs!

Answer 3

the book said the answers were -7 and 1...ok..

Factor completely the polynomial x^2+6x-7=0
(x+7)(x-1)=0
therefore x1= -7 and x2=1

Recheck all the adding and multiplying with the quadratic formula...

Cheers

Answer 4

*You don't need to use the Quadtratic Equation but, if your teacher/book says to do so....

First: you have three values for three coefficients...
a = 1
b = 6
c = -7

Sec: replace the values with their corresponding variables...

x = [- 6+/- √(6^2 - 4(1)(-7))] / 2(1)

x = [- 6+/- √(6^2 - 4(1)(-7))] / 2

x = [- 6+/- √(36 - 4(1)(-7))] / 2

x = [- 6+/- √(36 - 4(-7))] / 2

x = [- 6+/- √(36 + 28)] / 2

x = [- 6+/- √(64)] / 2

x = [- 6+/- 8] / 2

Third: you have two solutions > one has addition, the other has subtraction...

1. x = [- 6 + 8] / 2
x = 2/2
x = 1

2. x = [- 6 - 8] / 2
x= - 14/2
x = -7

Solutions: 1 and -7

Answer 5

the formula gives(-6 +-8)/2 = -7 and 1 because -b is -6

Answer 6

x=-b±√b^2-4ac/2a
a=1,b=6,c=-7
x=(-6±√(6)^2-4(1*-7))/2(1)
x=(-6±√36+28))/2
x=(-6±√64))/2
x=(-6±√64)/2
x=-6±8/2
(-6-8)/2, (-6+8)/2
x=-7 and 1
You should negative and positive integers for your answer.

Answer 7

x^2 + 6x - 7 = 0
x = 3.099363912
bound={-1EE99, 1EE99}

Answer 8

are u making b negative