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Plz solve the 20th question I am not able to understand the question itself .

Answer»

According to the question,


8x³ + 27y³ = 730 ---------- equation (i)


3x² + 3y² = 15 -----------equation (ii)


We have to find the value of (2X + 3Y)


LET us see what will be the CUBE of (2x + 3y)


i.e. (2x + 3y)³ = 8x³ + 3x²y + 3xy² + 27y³


or, we can also group it as: (8x³ + 27y³) + (3x²y + 3xy²)


Now, we have the value of this expressions,


(8x³ + 27y³) + (3x²y + 3xy²) = 730 + 15 = 745


But, it is not the answer, because we are bothered of (2x + 3y)³ and not (2x + 3y).


Therefore, if we do the cube root of it then we can get the value of (2x + 3y).


Therefore, (2x + 3y) = cube root of (2x + 3y)³ = cube root of 745 = 9.065 (Ans)


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