Question

Please help on this math question

Answer 1

`\large\boxed{C.\ (-2x^2-x+72)/(8x^2)}`

Explanation:

`(9)/(x^2)-(2x+1)/(8x)=(9\cdot8)/(x^2\cdot8)-((2x+1)\cdot x)/(8x\cdot x)\qquad\text{use the distributive property}\\\\=(72)/(8x^2)-(2x^2+x)/(8x^2)=(72-(2x^2+x))/(8x^2)=(72-2x^2-x)/(8x^2)\\\\=(-2x^2-x+72)/(8x^2)`