Question

if 7x-4y=11 and xy=3 find the value of 49x2+16y2
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Answer 1

Step-by-step explanation:

7x-4y=11

Squaring on both sides

(7x-4y)2=(11)2

49x2+16y2 -56xy =121

49x2+16y2=121 +56xy (xy=3)

49x2+16y2=121 +56 (3)

49x2+16y2=121 + 168

49x2+16y2 =289