If 5 is added to a number and the sum is doubled, the result is 7 less than the number. what is the number? write your answer as a number only.

The long jump record, in feet, at a particular school can be modeled by f(x) = 19.6 + 2.5ln(x + 1) where x is the number of years since records began to be kept at the school. what is the record for the long jump 11 years after record started being kept? round your answer to the nearest tenth.

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.