Chelsea is sewing handmade scarves for her sisters and friends. She has 7 1/2 yards of material and needs 2 1/4 yards of material for each scarf. How many scarves can she make with the existing material?

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.