Answer:
A. maximum value at 30
Step-by-step explanation:
−x² + 10x + 5
First, factor out the leading coefficient from the first two terms:
-1 (x² − 10x) + 5
Take half of the next coefficient, square it, then add and subtract the result.
(-10/2)² = 25
-1 (x² − 10x + 25 − 25) + 5
-1 (x² − 10x + 25) + 25 + 5
-1 (x² − 10x + 25) + 30
Factor the perfect square.
-1 (x − 5)² + 30
The equation is now in vertex form. This is a downwards parabola with a vertex at (5, 30). Since the parabola points down, the vertex is a maximum.
Answer:
$18.96
Step-by-step explanation:
Now the mechanics earn $14.2 per hour, which is 25.1% less than before.
If we say that the earnings before were 100% (to facilitate our calculation and understand better), now the earrings are (100-25.1)%=74.9%. This is, now they make the 74.9% of what they used to made.
So:
74.9% = 14.2
Let's multiply both sides by 100%/74.9% to make a 100% appear at the left side (see that multiply and divide by 74.9 will make it desapear):
74.9% *(100%/74.9%) = 14.2 * (100%/74.9%)
100% = 14.2 * (100%/74.9%)
And (100%/74.9%) is equal to 1/0.749, they are the same. So:
100% = 14.2 * 1/0.749
100% = 18.96
So, before the new manager they used to make $18.96. (you can verify by multiplying it by 74.9% and the result is 14.2)
Answer:
27 and 28
Step-by-step explanation:
