Question

If a-b =5 and ab =3 what is the value of a3- b3

Answer 1

Answer:

170

Step-by-step explanation:

• Given that a-b=5 and ab=3
• (a-b) 3=a3-b3-3ab(a-b)
• a3-b3=(a-b)3+3ab(a-b)
• By substituting given values, we get
• a3-b3=(5)3+3(3)(5)
• a3-b3=125+45
• a3-b3=170

Answer 2

Answer:

170

Step-by-step explanation:

given,

ab=3

a-b=5

solution:

(a-b)3=a3-b3-3ab(a-b)

(5)3=a3-b3-(3×3)(5)

125=a3-b3-9×5

125=a3-b3-45

a3-b3=125+45

a3-b3=170....Ans