If a-b=3and ab=4 find a³-b³
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Answered by
2
a - b = 3
=> a = 3 + b...............eq.1
ab = 4
=> a = b/4................eq.2
eq.1 = eq.2
=> b + 3 = b/4
=> b - b/4 = -3
=> 3b/4 = -3
=> 3b = - 12
=> b = -4
from eq.2 a = -4/4 = -1
now
a³ - b³
= (-1)³ - (-4)³
= -1 + 64
= 63
Answered by
1
Answer:
Step-by-step explanation:
a - b = 3
=> a = 3 + b...............eq.1
ab = 4
=> a = b/4................eq.2
eq.1 = eq.2
=> b + 3 = b/4
=> b - b/4 = -3
=> 3b/4 = -3
=> 3b = - 12
=> b = -4
from eq.2 a = -4/4 = -1
now
a³ - b³
= (-1)³ - (-4)³
= -1 + 64
=63
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