JUST REPOSTING THIS QUESTION UNTIL I GET A CORRECT ANSWER (Cause nobody will help me) XD

x = 15

Step-by-step explanation:

Simplifying

3x + (8x + 15) = 180

Reorder the terms:

3x + (15 + 8x) = 180

Remove parenthesis around (15 + 8x)

3x + 15 + 8x = 180

Reorder the terms:

15 + 3x + 8x = 180

Combine like terms: 3x + 8x = 11x

15 + 11x = 180

Solving

15 + 11x = 180

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-15' to each side of the equation.

15 + -15 + 11x = 180 + -15

Combine like terms: 15 + -15 = 0

0 + 11x = 180 + -15

11x = 180 + -15

Combine like terms: 180 + -15 = 165

11x = 165

Divide each side by '11'.

x = 15

Simplifying

x = 15

x=15  Hope this helps :)

Step-by-step explanation:

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