$f(x)=\dfrac{x-9}{x^2-81}\\\\\text{The domain:}\\\\x^2-81\neq0\qquad\text{add 81 to both sides}\\\\x^2\neq81\to x\neq\pm\sqrt{81}\\\\x\neq-9\ \wedge\ x\neq9\\\\Answer:\ \boxed{\text{All real numbers except -9 and 9}}\to\boxed{x\in\mathbb{R}-\{-9,\ 9\}}$

7 0

4 years ago

find the number of running and passing plays using substitution method 110 plays 3 yards per run 7 yards per pass total yards 37

Zinaida [17]

Let x be the number of running plays

Y be the number of passing plays

Since the total plays is 110

X + y = 110

And total yard is 378

3x + 7y = 378

Using the first equation

X = 110 – y and substitute to the 2nd equation

3(110 – y) + 7y = 378

And solve for y

Y = 12

Substitute to eqution 1

X = 110 – 12 = 98

7 0

3 years ago

Find the length of st

lutik1710 [3]

The legth is 3.6 :) it says it to the right

6 0

3 years ago