First solve for y:
Next graph the line....down 3, over 4...
The line should go through the 2nd and 4th quadrant.
The inequality is 'less than', so the solution is everything below the line.
Therefore the solution set lies in part of quadrant 2, all of quadrant 3, and part of quadrant 4.
Area of the trapezium = 1/2 (40 + 160) x 70
Area of the trapezium = 7000 ft²
One bag of fertilizer = 4000 ft²
Number of bags of fertilizer needed = 7000 ÷ 4000 = 1.75 bags.
Since only full bags of fertilizer can be bought, 2 bags of fertilizer are needed.
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Answer: 2 bags of fertilizer
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