A company models its net income, in thousands of dollars, with the function f (x) = x^2 + 2x 15, where x is the number of
units of its product sold. How many units of its product does the
company need to sell in order for the net income to equal $0?

sorry, i can't understand your question. will later if you describe more clearly!

: )

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116