20s= 140 I don’t know what this means I don’t understand if someone knows this please help me this is 6th grade math

s=7

Step-by-step explanation:

s is a variable. to isolate, or solve for s on its own, divide both sides by 20.

20s/20=140/20

s=7

So basically when you have a number like 20s it means 20 times s.

Now if you want to solve this problem you would need to know the value of s.

Since we don't know the value of s you need to multiply 20 by different numbers until you get 140

20 x 7 = 140.

So the value of s is 7.

Hope this 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

step-by-step explanation: yes