Question

If 2a+3b=15 and ab=10,then find out the value of 8a3+27b3

Answer 1

Hi,

Here is your answer !
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Given :

2a + 3b= 15 ----------(1)

ab = 10 -----------(2)

Cubing both sides in eq (1) , We get

(2a + 3b)³ = 15³

Using Identity,
(x + y)³ = x³ + y³ + 3xy(x + y)
We have

(2a)³ + (3b)³ + 3(2a)(3b) (2a + 3b) = 15³

8a³ + 27b³ + 18ab×(15) = 3375 [ from (1) ]

8a³ + 27b³ + 18×10×15 = 3375 [ from (2) ]

8a³ +27b³ + 2700 =3375

8a³ + 27b³ = 3375 - 2700

8a³ + 27b³ = 675

Answer 2

Answer:

Answer=675

Step-by-step explanation:

Hope this answer will help u