Question

if a-b=3 and ab=4,find the values of a³-b³??​

Answer 1

Answer:

hey frnd here is your answer

Step-by-step explanation:

here we will us formula-

a³-b³=(a-b)³+3ab(a-b).

we have values a-b=3 and ab=4.So now put value in formual ,we get

a³-b³=(a-b)³+3ab(a-b)

= (3)³+3(4)(3)

=27+36

a³-b³=63.

So frnd your final answer is 63.

I hope u get your answer

thnx for asking

plzz mark as brainlist...

Answer 2

a-b = 3 ---- eq.1

a = b+3,

ab = 4-------eq. 2

(b+3)b = 4

b^2 +3b = 4

b^2+3b-4 = 0

b^2-1b+4b-4 = 0

b(b-1)+4(b-1) = 0

(b+4)(b-1) = 0

b+4 = 0 b-1 = 0

b = -4 b = 1

Substitute b = 1 in eq.1

a-b = 3

a-1 = 3

a = 3+1

a = 4

a^3-b^3 = 4^3-1^3

=64-1

=63

Therefore, a^3-b^3 = 63