One soda and one taco costs $2.1. Two sodas and three tacos cost $5.15. Find the cost of a soda and a taco. Whoever answer this question will be the brainliest!!!

Soda costs $1.15 and taco costs $0.95.

Step-by-step explanation:

x + y = 2.1

2x + 3y = 5.15

Multiply the first equation by -2 to eliminate x

-2x - 2y = -4.2

2x + 3y = 5.15

Add

          y = 0.95

Find x with the original first equation

x + y = 2.1

x + 0.95 = 2.1

x = 2.1 - 0.95

x = 1.15

hope it helps :)

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

okay wait before i answer, is this for your points on a graph?