Question

if 3x -7y =10 and xy = -1 then the value of 9x²+49y²is​

Answer 1

Answer:

58

Step-by-step explanation:

Here if we square 3x-7y=10

(3x-7y)²=(10)²

9x²+49y²-2×7y×3x=100

9x²+49y²-42xy=100

xy=-1

9x²+49y²+42=100

9x²+49y²=100-42

9x²+49y²=58