What is the missing coefficient in the above expression? (3x^2-4x+7)(-2x^2+5x-9)=-6x^4+23x^3____x^2+71x-63
Expanding (3x^2-4x+7)(-2x^2+5x-9), we have
-6x^4+ 23x^3 - 61x^2 + 71x - 63
