I think c <span>If the unit weight is 0 pcf, the predicted porosity will be 118.910%.</span>
Answer:
It's A.
Step-by-step explanation:
Let's look at option A:
From the second equation y = -10 - x. Substituting in the first equation:
-10 - x = x^2 + 3x - 5
x^2 + 4x + 5 = 0
Checking the discriminant b^2 - 4ac we get 16 - 4*1*5 = -4 so there are no real roots. (A negative discriminant means no real roots).
So A has no real solution.
B.
x^2 + 3x - 5 = (20 - 4x)/5 = 4 - 0.8x
x^2 +3.8x - 9 = 0
b^2 - 4ac = (3.8)^2 - 4*1*-9 = 50.44 (positive) so there are real roots.
C.
x^2 + 3x - 5 = -9 - x
x^2 + 4x + 4 = 0
b^2 - 4ac = 4^2 - 4*1*4 = 0 so there are real roots.
88 seconds.
You are calculating a 20% decrease. This means you need to calculate 20% of 110.
First, calculate 10%, which is much easier. To do this, divide 110 by 10 (because you’re going from 100% to 10%, which is a division by 10, so you need to do the same to the 110)
110/10 = 11
However, now you need to get from 10% to 20%, so multiply by 2.
20% = 22
HOWEVER, YOU’RE NOT DONE HERE.
I know too many people who make the mistake in an exam of stopping here, myself included.
You’re working out a decrease! This is only the amount it has decreased by, not the final time.
To calculate the final time, you need to minus our value from the average.
So, 110-22 = 88
Therefore, it takes cashier A 88 seconds!
Hope this helps :)
Answer:
0.216
Step-by-step explanation:
