Answer:
The answer to your question is: x₁ = 9 ; x₂ = -2, third option
Step-by-step explanation:
The excluded values are those that make the denominator equal to zero.
To find the excluded values, just factor the denominator and equal to zero to find the roots.
Process
x² - 7x - 18
- Find to numbers that added gives -7 and multiply -18.
- These numbers are -9 and + 2, because
-9 + 2 = -7
and -9 x 2 = -18
(x - 9) (x + 2) = 0
x₁ - 9 = 0 x₂ + 2 = 0
x₁ = 9 x₂ = -2
Test
(9)² - 7(9) - 18 (-2)² - 7(-2) - 18
81 - 63 - 18 4 + 14 - 18
81 - 81 18 - 18
0 0
So.... there are 10 crayons and 8 are yellow.
This means that 8/10 of the crayons are yellow.
So the chance of picking a yellow one is 80%.
To get this, you need to do 8/10 and make it over 100, which is 80/100. Then, you turn this number into a percent by just dropping the 100 and adding a % to 80 (it's this easy if the bottom denominator is 100)
The work should look something like this;
8:10
8/10
80/100
80%
So, there is an 80% chance that the crayon you pick will be yellow. Any questions?
