Coefficient of $$x^{2}$$  in (x + 9)(6 - 4x)(4x - 7) is

A coefficient is a numerical or constant quantity placed before and multiplying the variable in an algebraic expression. Eg : In $$ax^2$$, coefficient is $$a$$

Expression : $$(x + 9)(6 - 4x)(4x - 7)$$

= $$(6x - 4x^2 + 54 - 36x)(4x - 7)$$

= $$(-4x^2 - 30x + 54)(4x - 7)$$

= $$4x(-4x^2 - 30x + 54) - 7(-4x^2 - 30x + 54)$$

= $$-16x^3 - 120x^2 + 216x + 28x^2 + 210x - 378$$

= $$-16x^3 - 92x^2 + 426x - 378$$

$$\therefore$$ Coefficient of $$x^2$$ = -92

=> Ans - (C)