We are looking to find the point where the curve discontinued
Step 1: Factorise both numerator and denominator (if possible)

Step 2: Recognise the common factor, which is

Step 3: Equate the common factor to 0


Answer: -5
3 x 15 = 45
3 x 14 = 42
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There are 14 packages.
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x = 42/3
-----> 3x=42
20 + (0.4 × 15) + 12 + (0.4 × 10) = 20 + 6 + 12 + 4 = 42
20 + 15 + 12 + 10 = 57
57 - 42 = 15
15 ÷ 57 × 100 = 1500 ÷ 57 = 26.3
Ans = $42.00, 26% off ...