The answer is,

And explanation is in the picture.
Answer:
x = 6
Step-by-step explanation:
The radius in this case measures; 20/2 = 10 since the diameter is 20.
The chord measuring 16 units has been bisected, hence each portion measures 8 units.
We now apply Pythagoras theorem since we are dealing with a right angled triangle with 2 given sides;
x^2 = 10^2 - 8^2
x^2 = 36
x = 6
Answer:
Step-by-step explanation:
The answer is o+ Hope this helped.
So I first subtracted 3x on each side, then 2x would equal 40 and then to find x, divide both sides by 2