Find the value of x, y, and z. Help!

Which speed is the fastest (use 1 mile ≈ 1.6 kilometers)? a. 12 miles/hour b. 18 feet/second c. 19 kilometers/hour d. cannot be determined

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.