Twice the difference of a number and 9 is 7

Pure acid is to be added to a 10% acid solution to obtain 72 L of a 20% acid solution. What amounts of each should be used? _L of pure acid solution and _L of 10% acid solution

What is the vertex? f (x) = 2 (x-5) ^2 + 12

Which of the students used the distributive property to simplify their expression? Select all that are true. A. 5 - 2 (4 + 9) - 11 5 - 2 (4) - 2 (9) - 11 5 - 8 - 18 - 11 -3 + (-18) + 11 -21 + (-11) -32 B.

Raina takes classes at both Westside Community College and Pinewood Community College. At Westside, class fees are $98 per credit hour, and at Pinewood, class fees are $115 per credit hour.

Write an equivalent expression for the expression (a+b) (2+y)

Henry is four times older than James. Next year, Henry will be three times older than James will be. How old are Henry and James now? a. James is 3 years old; Henry is 4 years old. b. Henry is 4 years old; James is 3 years old. c.

Wayne and Winston are scuba diving and are ascending to the surface. The function y = 30x - 105 represents Wayne's elevation in feet in terms of the time in minutes he ascends.

What is 470,000 in scientific notation

Why do you suppose the United States still uses the English System for everyday measurements, while almost every other country uses Sl? Give several possible reasons

Solve the system of equations by graphing. x+y=3, y=2x-15