Question

if(3a+2y)=7 ay=2m find 27a^3+8y^3​

Answer 1

27a³ + 8y³ = 343 - 168m

Step-by-step explanation:

We are given that (3a + 2y) = 7 and ay = 2m and we have to find the value of 27a³ + 8y³.

Now, (3a + 2y) = 7 ........ (1)

Cubing both sides we get,

(3a)³ + (2y)³ + 3(3a)(2y)(3a + 2y) = 7³

⇒ 27a³ + 8y³ + 12(ay)(7) = 343 {Since, (3a + 2y) = 7, from equation (1)}

⇒ 27a³ + 8y³ = 343 - 12(2m)(7)  {Since, ay is given to be 2m}

⇒ 27a³ + 8y³ = 343 - 168m (Answer)