Simply the attached question

Answer:
=x⁴−x³−14x²
Step-by-step explanation:
x²(3x²+5x−4)−2x²(x²+3x+5)
=(x²)(3x²)+(x²)(5x)+(x²)(−4)+−2x⁴+−6x³+−10x²
=3x⁴+5x³+−4x²+−2x⁴+−6x³+−10x²
=3x⁴+5x³+−4x²+−2x⁴+−6x³+−10x²
=(3x⁴+−2x⁴)+(5x³+−6x³)+(−4x²+−10x²)
=x⁴+−x³+−14x²
=x⁴−x³−14x²