The function is:
f ( x ) = x² - x - 72
This is a quatdratic function. So we can find the zeroes of the function with the formula:
x 1/2 = ( - b +/- √(b² - 4 ac) ) / ( 2a )
And we have: a = 1, b = - 1 and c = - 72
x 1/2 = ( 1 +/- √((-1)² - 4 · 1· ( - 72 )) ) / 2
x 1/2 = ( 1 +/- √( 1 + 288 ) ) / 2
x 1/2 = ( 1 +/- √289 ) / 2
x 1/2 = ( 1 +/- 17 ) / 2
x 1 = ( 1 - 17 ) 2 = - 16 / 2 = - 8
x 2 = ( 1 + 17 ) / 2 = 18 / 2 = 9
Answer: The zeroes are - 8 and 9.
An example should make this clear.
If $50 is 40% what is the value of the whole amount?
Answer:- Whole amount = 100^%
By proportion this = (100/ 40) * 50
= 2.5 * 50
= $125 (answer)
Answer:
The second one (2) is a lie
Step-by-step explanation:
The quantities are all proportional, with 4 donuts costing one dollar being consistant. With this, we can multiply the amount of donuts to 40, and through what we know, we can find that the donuts will cost 10 dollars. This leaves only (2) left.
Answer:
step 2
Step-by-step explanation:
we have
---> given problem
step 1
Move the constant to the right side
the step 1 is correct
step 2
Complete the square
<u><em>The step 2 is not correct</em></u>
step 3
Rewrite as perfect squares
step 4
take square root both sides
step 5
Find the values of x
Multiple each number I think
