By using horizontal method,

We have;

(2x²+ 3x – 7) ×(3x² – 5x + 4)

= 2x²(3x² – 5x + 4) + 3x(3x² – 5x + 4) – 7(3x² – 5x + 4)

= 6x⁴ – 10x³ + 8x² + 9x³ – 15x² + 12x– 21x² + 35x – 28

Now, putting equal power terms together, we get,

= 6x⁴ – 10x³ + 9x³ + 8x² – 15x²– 21x² + 35x + 12x– 28

= 6x⁴ – x³ – 28x² + 47x – 28