Question 74278
can you check my answer? 
7x^2+6x from 9x^2-3 
9x^2-3
7x^2-6
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=2x^2+3
You subtracted 7 from 9 and got 2 correctly.
You should subtract -6 from -3 and get +3
The Rule is : "change the sign of the -6 to +6 and then add" to get +3
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Cheers,
Stan H.