When i square - 4 it says the answers - 2i whats the i stand for

Medical researchers have determined that for exercise to be beneficial, a person's desirable heart rate, R, in beats per minute, can be approximated by the formulas R = 143 - 0.65a for women R = 165 - 0.

Can a triangle be formed with three sides of equal lengths? Explain.

Multiply. Type your answer in the box. Do not use any spaces. (+19) x (-3) =

Tom built a backyard cage for his new puppy the length of the pen was 6 1/4 meters and the width was 4 1/2 what is the area of

Which has the greater area: a 6 6-centimeter by 4 1 2 412-centimeter rectangle or a square with a side that measures 5 5 centimeters?

Naomi wants to buy a new computer for $840. She is considering two payment plans that require weekly payments. Which plan will pay for the computer faster? Plan A : $180 down $60 per payments Plan B: $0 down $70 per week payments

In the library, 6 students are working on math. Of those 6 students, 2/3 of them are working on fraction. How many students are working on fractions?

What is the quotient of - 1 4/5 and 2 1/4?

What is the exact distance from parentheses - 4, - 2 what is the exact distance from parentheses - 4, - 2 to parentheses four, six

Which number produces an irrational number when multiplied by 0.5