a³-b³ = 81 and a-b = 3 then what is the value of a²+b²
Answers
Answered by
8
Step-by-step explanation:
a3-b3 = 81
a_b=3
a2-b2= 25
Answered by
32
Answer:
a²+b² = 21
Step-by-step explanation:
a³-b³ = 81 a-b = 3
a³ - b³ - 3ab(a-b) =81
(3)³ - 3ab x 3 = 81
27 + 9ab = 81
9ab = 81 - 27
9ab = 54
ab = 54/9
ab=6
a²+b² = 3² + 2 x 16
= 9 + 12= 21
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