The equation represents height as a function of time.
The bullet was in the air for 75 seconds.
The equation is given as:
The time spent in the air is the time it takes the bullet to land on the ground.
When the bullet is on the ground, the height is:
So, we have:
Factor out t
Split
or
represents when the shot is fired.
So, we solve for t in
Collect like terms
Divide both sides by 16
Hence, the bullet was in the air for 75 seconds
Read more about height and time at:
Answer:
A and E
Step-by-step explanation:
Given
20x² - 26x + 8 = 0 ( divide through by 2 )
10x² - 13x + 4 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 10 × 4 = 40 and sum = - 13
The factors are - 5 and - 8
Use these factors to split the x- term
10x² - 5x - 8x + 4 = 0 ( factor the first/second and third/fourth terms )
5x(2x - 1) - 4(2x - 1) = 0 ← factor out (2x - 1) from each term
(2x - 1)(5x - 4) = 0
Equate each factor to zero and solve for x
2x - 1 = 0 ⇒ 2x = 1 ⇒ x = → E
5x - 4 = 0 ⇒ 5x = 4 ⇒ x = → A