The function is given by the formula y (x) = 2x find y at values of x: 10 -4.5 15 -21.

If the function is specified by the formula y = f (x), in order to find the value of the function for the given value of the argument, you need to substitute this value in the function formula instead of each x and calculate the value of y.

Solution:

at x = 10, y = 2 * 10 = 20;

at x = -4.5, y = 2 * (-4.5) = – 9;

at x = 15, y = 2 * 15 = 30;

at x = -21, y = 2 * (-21) = -42.

Answer: y (10) = 20, y (-4.5) = -9, y (15) = 30, y (-21) = -42.