Four less than a number squared

Restating the conditions of problem 1, the cost to buy t-shirts is $5.00 for the first 10 shirts, $4.00 for each additional shirt up to 50, and $3.00 for each shirt above 50. if you purchase 100 shirts, what is the average cost per shirt?

What is the solution to the system of equations? Use the substitution method. y-3x=7 21+9x=3y A. There is no solution B. There are an infinite number solutions C. The solution is {1,10} D. The solution is {28,0}

What value of z makes the statement true? - (z + (-17)) = 12 + 17 A. -46 B. -12 C. 12 D. 46

Express 12.4 as a fraction - show your work.

Simplify the expression. - - (9m - 7)

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.