Y= ax+b
when x=3, y=11 and when x= -2, y=11
3a+b=11
-2a+b=11 | * -1
3a+b=11
2a-b=-11
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5a=0, a=0:5, a=0
⇒ b=11
y=11 for every x
So ( 1,11) or (2,11) are also points on the graph
A+c = 150
10.25a+7.75c = 1470
Symmetrical because the numbers in a bar graph show sort of a pyramid-like shape, rather than a skewed or flatter shape.
