Negative 45 or -45 because different signs with multiplication are always negative
I believe the answer would be 13.75 but i’m not completely sure on this so correct me if i’m wrong
The answer tour question is D
Step-by-step explanation:
The slope-intercept form of an equation of a line:

<em>m</em><em> - slope</em>
<em>b</em><em> - y-intercept (0, b)</em>
<em />

11*57+X(1+2+3+.....+56)
=11*57+X(1+56)*56/2
=627+1596X
=19779
X=(19779-627)/1596=12
Your answer is C