If 5x + 9y = 5 and 125x3 + 729y3 = 120, then the value of the product of x and y is?

125x3 + 729y3 = 120

5x + 9y = 5Cubing both sides

(5x + 9y)3 = (5)^3125x3 + 729y3 + 3 × 5x × 9y(5x + 9y) = 125125x3 + 729y3 + 135xy × 5 = 125 120 + 135xy × 5 = 125135xy × 5 = 5xy = 1/135

Answer xy =1/135

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125x3 + 729y3 = 120

5x + 9y = 5

Cubing both sides

(5x + 9y)3 = (5)^3

125x3 + 729y3 + 3 × 5x × 9y(5x + 9y) = 125

125x3 + 729y3 + 135xy × 5 = 125

120 + 135xy × 5 = 125

135xy × 5 = 5

xy = 1/135

Answer xy =1/135