find the first derivative with respect to x, of the following function using first principle f(x) = 6 + 5x - x^2

Pear co.’s income statement for the year ended december 31, as prepared by pear’s controller, reported income before taxes of $125,000. the auditor questioned the following amounts that had been included in income before taxes: equity in earnings of cinn co. $ 40,000 dividends received from cinn 8,000 adjustments to profits of prior years for arithmetical errors in depreciation (35,000) pear owns 40% of cinn’s common stock, and no acquisition differentials are relevant. pear’s december 31 income statement should report income before taxes of