if a+b=8 and a^2+b^2=4 find a^3+b^3
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2
Answer:
320
Step-by-step explanation:
first find ab
formula ......
a²+b² = (a+b)²-2ab
4 = (8)²- 2ab
4 = 64-2ab
2ab = 64÷4
ab = 8
then in last we find a³+b³
formula for a³+b³
# a³+b³ = (a+b)³-3ab(a+b)
a³+b³ = (8)³-3(8)×8
= 512-192
a³+b³ = 320
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