Question

a-b=3, ab=4
find
a3-b3​

Answer 1

Answer:

(a-b) ³=a³-b³-3ab(a-b)

(a-b) ³=a³-b³-3×4(a-b)

(3)³= a³-b³-12×3

27=a³-b³-36

27+36=a³-b³

63=a³-b³

Answer 2

Answer:  63

Step-by-step explanation:

a^3 -b^3= (a-b)(a^2 + b^2 +ab) -------- (1)

(a-b)^2= 3^2=9

a^2 + b^2 - 2ab= 9

a^2 + b^2 = 9+8= 17

therefore, putting in the values

we get 3(17+4)= 3 *21= 63