Maria walks a round-trip of 0.75 mile to school everyday. how many miles will she walk in 4.5 days?

You just multiply the two together. So, 4.5x0.75=3.375

She walked 3.375 miles in 4.5 days.

a complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is a solution of the equation x2 = −1. because no real number satisfies this equation, i is called an imaginary number. has no real solution, since the square of a real number cannot be negative.