Question

if x-y=4 and XY=21.find the value of x3-y3
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Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

316

Step-by-step explanation:

according to the formula

(x - y)³ = x³ - y³ - 3xy (x - y)

in the question it is given that, x - y = 4 and xy = 21

∴

4³ = x³ - y³- 3 × 21 × (4)

64 = x³ - y³ - 63 × 4

64 = x³ - y³ - 252

64 + 252 = x³ - y³

∴ x³ - y³ = 316