If a=117+b^3 and a=3+b, then find the value of a+b?
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Answered by
1
Answer:
dtydyuffufts
Step-by-step explanation:
studfuiffhf
Answered by
1
Step-by-step explanation:
Solution: a³=117+b³ and a=3+b
a^3-b^3 = 117, or
(a-b)(a^2+ab+b^2) = 117 …(1)
a=3+b or a-b = 3 …(2)
Hence (1) becomes 3(a^2+ab+b^2) = 117, or
a^2+ab+b^2 = 39, or
a^2+2ab-ab+b^2 = 39
(a+b)^2 - ab = 39, or
(a+b)^2 = 39+ab, or
a^2+2ab+b^2 = 39+ab …(3)
(a-b)^2 = 3^2 = 9, or
a^2–2ab+b^2 = 9 …(4)
Subtract (4) from (3)
4ab = 30+ab or
3ab = 30, or
ab = 10.
(3) becomes (a+b)^2 = 39+10 = 49, or
a+b = ±7. Answer.
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