Answer:
option (3) is correct.

Step-by-step explanation:
Given 
We have to solve for e.
Consider the given statement,

Cross multiply, we get,

Taking square root both sides , we get,

We know square root of 9 is 3.

Thus, option (3) is correct.

X + x + x + x - 20 is equivalent to 4x - 20 because you can add the like terms, or the x's.
Check the picture below.
to get the equation of any straight line, we simply need two points off of it, so let's use those in the picture


Answer:
Four times his sister's age would be 4b. his age is two years less, so we need to subtract 2.
put together, this is 4b - 2.
We need a pic of the line plot to complete and answer this