Consider strings of four decimal digits. Which rule must be used to find the number of strings of four decimal digits that have exactly three digits that are 9s? multiple choice the sum rule the subtraction rule the product rule the division rule How many strings of four decimal digits have exactly three digits that are 9s?

Write the pair of fractions as a pair of fractions with a common denominator

I've been working on this for a few days and i just don't understand, it's due in a few hours. you.the direction of a vector is defined as the angle of the vector in relation to a horizontal line. as a standard, this angle is measured counterclockwise from the positive x-axis. the direction or angle of v in the diagram is α.part a: how can you use trigonometric ratios to calculate the direction α of a general vector v = < x, y> similar to the diagram? part bsuppose that vector v lies in quadrant ii, quadrant iii, or quadrant iv. how can you use trigonometric ratios to calculate the direction (i.e., angle) of the vector in each of these quadrants with respect to the positive x-axis? the angle between the vector and the positive x-axis will be greater than 90 degrees in each case.part cnow try a numerical problem. what is the direction of the vector w = < -1, 6 > ?

You are riding your bike and notice the square sign above. you mentally draw a straight line from point a to c. describe the angle relationship between dca and bca