if x = -4, find the value of the expression 3x^2 -2x +1/x.

Question

If x = -4, find the value of the expression 3x^2 -2x +1/x.

Answer 1

Hi Kevin; 3x^2 -2x + 1/x x=-4 In mathematics, the Order of Operations is... Parentheses...none in the original equation... Exponents...x^2 Multiplication...3 * x^2 and 2*x Division...except for the fraction, this operation will not be performed. Addition...+1/x Subtraction...-2x It is acronymed as PEMDA. It can be easily remembered as Please excuse my Dear Aunt Sally. 3(-4)^2 -2(-4) + 1/(-4) The parentheses I am herewith using is for convenience and does not apply to PEMDA. We begin with the exponent... 3[(-4)(-4)] - 2(-4) + 1/(-4) 3(16) - 2(-4) + 1/(-4) Multiplication... 48- (-8) + 1/(-4) This is also... 48 + 8 - 1/4 Addition... 56 - 1/4 Subtraction... 55 3/4