6X plus 3Y equals 3 3x minus Y equals four

Step-by-step explanation:

6x + 3y = 3 simplify by dividing both sides by 3 2x + y = 1

3x - y = 4 the 1st equation has a positive y, the 2nd has a negative y. Use elimination

to reduce them down to a single variable equation:

2x + y = 1

3x - y = 4

5x = 5 solve

X = 1 substitute back in to one of the original equations to find y

3x - y = 4

3(1) - y = 4

- y = 1

y = -1 (1,-1)

took the test it's 94

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