Help a girl out pls What are the exact solutions of x2 - X-4 = 0, where -b + √b² - 4ac X= 2a Ox= -115 2 Ox= 11 15 2 O x = 1:17 2 0x==137​

    1 ± sqrt(17)

 x =

            2

Step-by-step explanation:

x^2 - x - 4 =0

Using the quadratic equation

     -b ± sqrt(b^2 -4ac)

 x =

            2a

Where ax^2 +bx +c  

We know a =1  b = -1  c = -4

     -(-1) ± sqrt((-1)^2 -4(1)(-4))

 x =

            2(1)

     1 ± sqrt(1 +16)

 x =

            2

     1 ± sqrt(17)

 x =

            2

es todo o no o que hacen hola

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12

i dont know sorry

step-by-step explanation: