How is a²-4a-21 expressed in factored form?

(x-1) (x+21)

(x-21) (x+1)

(a-7) (a+3)

(a-3) (a+7)

Three friends all have ages that are consecutive integers. The sum of their ages is 180. What is the age of the oldest friend?

8. An apple is launched directly upward at 64 feet per second from a platform 80 feet high The equation for this apple's height h at time 7 seconds after launch is h = - 1612 + 64t + 80. How long did it take the apple to reach the ground?

A used book store buys a hardback book for $1.50 and then sells it for $5. Over time, the store sells the same number of books it buys. The store manager can use the equation P (x) = 5x-1.

The original value of the car is $18,000 and it depreciates by 50% each year what is the value of the car after three years

Find the simple interest in a savings that pays 5% interest if 500$ is deposited for 4 years

What is (57/tan30°) m^2

How do you find zeros when given a quadratic relation in vertex form

3x²+5x+2 factor the expression and find the greatest common factor

If f (x) = 3x - 2 and g (x) = x2 + 1, find (+6) x).

A boy is 17 years old and his sister is twice as old. when the boy is 23 years old what will be the age of his sister?