Question

If 2x + 3y = 10, xy = 4, find 8x^3 + 27y^3​

Answer 1

Answer:

8x^3+27x^3

(2^3 .x^3)+(3^3.x^3)

2x^3+3x^3

=5x^3

Answer 2

Given

⇒2x + 3y = 10

⇒xy = 4

To Find

⇒8x³ + 27³

Formula

⇒(a+b)³ = a³+b³+3ab(a+b)

Now Let

⇒2x = a and 3y = b

Put the value on formula

⇒(2x+3y)³ = (2x)³ + (3y)³ + 3×2x×3y(2x+3y)

⇒(10)³ = 8x³ + 27y³ + 18xy(10)

⇒100 = 8x³ + 27y³+ 18×4×10

⇒100 = 8x³ + 27y³ + 40×18

⇒100 = 8x³ + 27y³ + 720

⇒8x³ + 27y³ = 100 - 720

⇒8x³ + 27y³ = -620

Answer

⇒8x³ + 27y³ = -620