The obvious answer to this would be 10.
The most simple way to do it would be taking out 3 x from each side of the equation and do 20 = 10 + _
Another way would be to actually solve it.
Let us put into the situation that the unknown variable would be y. The equation then would look like this.
3 x 20 = 3 x (10 + y)
Then solve
3 x 20 = 3 x (10 + y)
-------- ---------------
3 3
20 = 10 + y
20 - 10 = y
10 = y
10 would be the answer
What are the options they have given?
Answer:
a = 10/3
Step-by-step explanation:
This can be written as:

Anything to the power of 1/3 means to find the cube root. We can simplify this to:
I just multiplied 4 and 1/3 (because of the second index law
). Now, we can add the powers because the bases are the same and we are multiplying (first index law):

a = 10/3
Hope this helps!

-----------------------------------------
Answer:
There is a scale factor of 1
Step-by-step explanation:
the ratio 1:1 means that there is no difference between the two triangles, and that they are congruent.