Which of the following equations have only one solution? Select all correct answers
x²-x-6=0
5x^2 + 20 x + 20 = 0
9x^2 - 25 = 0
4x^2 + 4 x = 0
x^2 + 6 x + 9 = 0

What is [tex] {7}^{98 + \sqrt{4} } - 3 \times (64 \div 2 + 4 - 36) \times a = a + 36[/tex]?

The blue whale is the largest animal living on the earth. the average blue whale measures 100 feet long (30 meters) and weighs 300,000 pounds (136,000 kilograms). a whale’s head is 1⁄3 of the length of its body. a new baby whale is 1⁄4 the length of a grown whale. the average man is 1⁄17 the length of a blue whale, and 1⁄1,818 its weight. a human baby measures 1⁄4 of the length of an adult. calculate the following information: how long is a whale’s head? how long is a new baby whale? how tall is the average man? how much does the average man weigh? how tall is the average human baby?

In what organelle does photosynthesis take place?