It's 26 because the pattern is adding 5. To find the pattern, just subtract the numbers from the ones before so 11-6 and 21- 16 which both equal 5. Then just add 5 to the last number and you'll find it to be 26.
What I’m I supposed to be looking for??
Since TSQ and QSR are supplementary, they give 180 when summed. TSQ is 150, so QSR must be 30.
Therefore, you have

Answer:
y = -9/5x + 9/5
Step-by-step explanation:
From this points, we can determine the slope and the y-intercept.
First, we do: y/x - y1/x1
=> 0/3 - (3 - 2)
=> 0-3/ 3 + 2
=> -3/5
So the slope of the equation is -3/5.
The equation is: y = mx + b
In this equation "m" = slope.
=> b = constant
Now we take the x and y points from the above numbers.
=> Let's take 3 as x and 0 as y.
=> 0 = -3/5 *3 + b
=> 0 = -9/5 + b
=> Take the -9/5 to the other side
=> 9/5 = b
So, the constant number which is not multiplied by the x is 9/5
Now, our equation looks like:
y = -9/5x + 9/5
If you have any doubts about this question, ask me the comments and I will answer it as soon as possible.