3x+2x2+9y+8 I need this question it’s urgent

Ben walks 25 miles from home to work. If he walks the first 5 miles in 1 hour, the second 5 miles in 1.4 hours, the third 5 mile

natka813 [3]

Answer:

The total time taken to complete 25 miles is 7.6 hours.

Solution:

Ben walks 5 miles in 1 hour,

Second 5 miles in 1.4 hours,

Third 5 miles in 1.7 hours,

Last 5 miles in 1.8 hours

So he walked total 20 miles in (1+1.4+1.7+1.8) hours = 5.9 hours = 6 hours (approximately)

So his average speed is $\left(\frac{20}{6}\right)$ miles/hours = 3.33 miles/hours.

i.e. he travels 3.3 miles in 1 hour,

Then, he travels 1 miles in $\left(\frac{1}{3.3}\right)$ hours

Hence the total time he will take to walk 25 miles is $\left(25 \times\left(\frac{1}{3.3}\right)\right) \text { hours }$ $\Rightarrow \left(\frac{25}{3.3}\right) \text { hours } = 7.5757 hours$

That is approximately 7.57 or 7.6 hours.

8 0

3 years ago

WILL MARK BRAINLIEST what is the domain of (f/g) (x)?

tatyana61 [14]

Given that $f(x) = \sqrt{7-x}$ and $g(x) = \sqrt{x + 2}$ , we can say the following:

$\Bigg(\dfrac{f}{g}\Bigg)(x) = \dfrac{f (x)}{g(x)} = \dfrac{\sqrt{7 - x}}{\sqrt{x+2}}$

Now, remember what happens if we have a negative square root: it becomes an imaginary number. We don't want this, so we want to make sure whatever is under a square root is greater than 0 (given we are talking about real numbers only).

Thus, let's set what is under both square roots to be greater than 0:

$\sqrt{7 - x} \Rightarrow 7 - x \geq 0 \Rightarrow x \leq 7$

$\sqrt{x + 2} \Rightarrow x + 2 \geq 0 \Rightarrow x \geq -2$

Since both of the square roots are in the same function, we want to take the union of the domains of the individual square roots to find the domain of the overall function.

$x \leq 7 \,\,\cup x \geq -2 = \boxed{-2 \leq x \leq 7}$

Now, let's look back at the function entirely, which is:

$\Bigg( \dfrac{f}{g} \Bigg)(x) = \dfrac{\sqrt{7 - x}}{\sqrt{x+2}}$

Since $\sqrt{x + 2}$ is on the bottom of the fraction, we must say that $\sqrt{x + 2} \neq 0$ , since the denominator can't equal 0. Thus, we must exclude $\sqrt{x + 2} = 0 \Rightarrow x + 2 = 0 \Rightarrow x = -2$ from the domain.