What basic math skills should I know for grade 9 math

Mario's weekly poker winnings have a mean of $353 and a standard deviation of $67. Last week he won $185. How many standard deviations from the mean is that?

What is 99 to the 22 power?

Dana buys and sells superhero themed shirts, jeans and designer dresses. She bought two shirts for $5.00 each and later sold them for $9.00 each. She bought three pairs of jeans for $9.00 each and later sold them for $17.00 each.

Determine g (x + a) - g (x) for the following function. g (x) = - 5x^2-3x+2 g (x + a) - g (x) = ?

Systems of equations with different slopes and different y-intercepts have one solution. A. Always B. sometimes C. never

Andrea told Michelle that less than 1/2 is 5/12. Michelle said she is mistaken, who is correct? Explain why you chose your answer

Solve for b. 8b-1=24b+4

876.34 rounded to the nearest thousandth

A triangle in the xy-coordinate plane has vertices with coordinates (7, 0), (0, 8), and (20, 10). what is the area of this triangle

What is the value of the product (3 - 2i) (3 + 2i) ?