15p+15p+25p=30p+25p=55p
1. Domain.
We have
![x^2-2x-3](https://tex.z-dn.net/?f=x%5E2-2x-3%20)
in the denominator, so:
![x^2-2x-3\neq0\\\\(x^2-2x+1)-4\neq0\\\\(x-1)^2-4\neq0\\\\(x-1)^2-2^2\neq0\qquad\qquad[\text{use }a^2-b^2=(a-b)(a+b)]\\\\(x-1-2)(x-1+2)\neq0\\\\ (x-3)(x+1)\neq0\\\\\boxed{x\neq3\qquad\wedge\qquad x\neq-1}](https://tex.z-dn.net/?f=x%5E2-2x-3%5Cneq0%5C%5C%5C%5C%28x%5E2-2x%2B1%29-4%5Cneq0%5C%5C%5C%5C%28x-1%29%5E2-4%5Cneq0%5C%5C%5C%5C%28x-1%29%5E2-2%5E2%5Cneq0%5Cqquad%5Cqquad%5B%5Ctext%7Buse%20%7Da%5E2-b%5E2%3D%28a-b%29%28a%2Bb%29%5D%5C%5C%5C%5C%28x-1-2%29%28x-1%2B2%29%5Cneq0%5C%5C%5C%5C%0A%28x-3%29%28x%2B1%29%5Cneq0%5C%5C%5C%5C%5Cboxed%7Bx%5Cneq3%5Cqquad%5Cwedge%5Cqquad%20x%5Cneq-1%7D)
So there is a hole or an asymptote at x = 3 and x = -1 and we know, that answer B) is wrong.
2. Asymptotes:
![f(x)=\dfrac{x-3}{x^2-2x-3}=\dfrac{x-3}{(x-3)(x+1)}=\boxed{\dfrac{1}{x+1}}](https://tex.z-dn.net/?f=f%28x%29%3D%5Cdfrac%7Bx-3%7D%7Bx%5E2-2x-3%7D%3D%5Cdfrac%7Bx-3%7D%7B%28x-3%29%28x%2B1%29%7D%3D%5Cboxed%7B%5Cdfrac%7B1%7D%7Bx%2B1%7D%7D)
We have only one asymptote at x = -1 (and hole at x = 3), thus the correct answer is A)
Answer:
neither do I'm stuck on that one
At Gino's you pay $16 plus $8 per pizza.
At Venetian's you pay $24 plus $6 per pizza.
Let the number of pizzas be x.
At Gino's you pay 16 + 8x
At Venetian's you pay 24 + 6x
Set the two costs equal and solve for x to find out the number of pizzas for which both costs are the same.
16 + 8x = 24 + 6x
16 + 2x = 24
2x = 8
x = 4
Each place gives you a free pizza.
4 pizzas plus the free pizza equals 5 pizzas.
If you need 5 pizzas (including the free one), both parlors cost the same.
If you need fewer than 5 pizzas, use Gino's.
If you need more than 5 pizzas, use Venetian's.
Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.