ABC is a straight angle. Which equation can be used to find the measure of the unknown angle?

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?

How are algebraic expressions evaluated using substitution?