Answer:
you talking to specific people or can anyone join
Step-by-step explanation:
X-10>15.........................................
Answer: y = -3(x + 
)² + 
, 
, 
<u>Step-by-step explanation:</u>
First, you need to complete the square:
y = -3x² - 5x + 1
<u> -1 </u> <u> -1 </u>
y - 1 = -3x² - 5x
y - 1 = -3(x² + 
y - 1 + -3(
) = -3(x² + + )
↑ ↓ ↑
= 
y - 1 - 
= -3(x + )²
y - 
- = -3(x + )²
y - = -3(x + )²
y = -3(x + )² +
Now, it is in the form of y = a(x - h)² + k <em>where (h, k) is the vertex</em>
Vertex = ,
let h= history books
science books = s
h=2s there are 2 times as many history as science so to get them equal we double the science
h+s=81 there are 81 total history and science books
2s+s=81 substitute 2s for h in the above equation
3s = 81 combine like terms
s = 27
There are 27 science books
h=2s
h=2(27)
h=54
there are 54 history books
79.57 times 12% = 70.02
70.02 times 7.75% = 5.43
70.02 plus 5.43 = 75.43
