Which system of linear inequalities is represented by the graph? y > x + 3 and 3x – y > 2 y > x + 3 and 3x – y > 2 y > x + 3 and 3x + y > 2 y > x + 3 and 2x – y > 2
Question
Answer:
Step 1: Find equations of the linesRed, solid line:
Find slope: 1square in y / 3 squares in x => slope = 1/3
y-intercept : (0,3)
Equation of the line: one of the following:
y=x/3+3 .................(1a)
3y=x+9 .................(1b)
x-3y+9=0 .................(1c)
Black, dotted line:
Slope = 3 squares in y / 1 square in x => slope = 3
y-intercept (0,-2)
Equation of the line: one of the following:
y=3x-2.....................(2a)
3x-y=2..................(2b)
2. Find location of region, i.e. greater or less than
Red region:
The region is above the solid line, i.e. we look for y>= .....
From equation (1a), we change the equality to >=, or
y >= x/3+3 [>= because line is solid]
Black region:
The region is to the right of the dotted line, we look for x > ...
From equation (2b),, we change equality to >, or
3x-y > 2 [ > because line is dotted ]
Note: All the given answers have common typos, namely
the first inequality should read y > x/3+3 or y>=x/3+3
the second inequality should read 3x-y > 2 or 3x-y >=2
The way question is presented, all the answer choices are the same (and incorrect).
@lazalewagoner you still have time to correct the answer choices.
solved
general
10 months ago
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