Question 284038
It's linear, meaning they're straight lines.  2 points for each are needed.
x + 2y = 3
x = 3 - 2y
Pick 2 values for y and find x.
y....x
0....3 --> (0,3)
3....-3 --> (-3,3)
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Plot the 2 points, draw a line thru them.
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-7x + 3y = -21
y = (7/3)x - 7
Pick 2 values for x and find y.
Plot the points, draw a line thru them
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Where the lines intersect is the solution.