if 3a+7b=20 and ab=4,then the value of 9a^2+49b^2 is
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Answer:
9a^249b^2=232
Step-by-step explanation:
3a+7b=20
(3a+7b)^2=20^2
9a^2+49b^2+2(3a)(7b)=400
9a^2+49b^2+42ab=400
9a^249b^2+168=400
9a^249b^2=400-168=232
onelifelove4:
the + sign has been left by mistake in last two lines so please consider that. sorry for the inconvinience
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