Is 2(–2) + 6(2) equivalent to (–3)(–3) + (–1)(1)? Let negative numbers be represented with a "–" symbol and positive numbers be represented by "+" symbol. Use a pictorial model to justify your answer.

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

The high temp today was 62°. when nighttime comes, the temp will drop 40°. by 4am the temp will drop an additional 40°. what is the temp at 4am?