For the formula in the following Exercise, is y directly proportional to x ? If so, give the constant of proportionality.

$$y=\sqrt{5 x}$$

In the following Problem, write an equation representing the situation if p is the price of a meal in dollars.

he cost of a meal plus a 20 % tip is 10.80 dollars.

In the following Problem, write an equation representing the situation if p is the price of a meal in dollars.

The cost of three meals plus 5 dollars tip is 3 dollars.

One algebra class has a total of A students, while a second class has B students, where A is larger than . What does the expression in the following Problem represent in practical terms?

A-B

Evaluate and simplify the expressions in the following Problem given that $w(s)=4-7 s$.

$$3 w(s-5)$$

In the following Problem, write an equation representing the situation if p is the price of a meal in dollars.

The cost of two meals is 18 dollars.

A car with tire pressure $P$ lbs/in ${ }^2$ gets gas mileage $g(P)$ (in mpg). The recommended tire pressure is $P_0$. What do the expressions tell you about the car's tire pressure and gas mileage?

$$g\left(P_0\right)-g\left(P_0-5\right)$$

One algebra class has a total of A students, while a second class has B students, where A is larger than . What does the expression in the following Problem represent in practical terms?

57. A+B

The equation in the following Exercise can be solved by performing two operations on both sides. State the operations in order of use and solve the equation.

$$(p-2)^3=125$$

A car with tire pressure $P$ lbs/in ${ }^2$ gets gas mileage $g(P)$ (in mpg). The recommended tire pressure is $P_0$. What do the expressions tell you about the car's tire pressure and gas mileage?

$$g\left(0.9 P_0\right)$$

Suppose $P$ and $Q$ give the sizes of two different animal populations, where $Q>P$. Which of the given pair of expressions is larger? Briefly explain your reasoning in terms of the two populations. $P+50 t$ and $Q+50 t$

The equation in the following Exercise can be solved by performing two operations on both sides. State the operations in order of use and solve the equation.

$$\frac{A^2}{7}=3$$

Which of the equations in parts (a)-(d) are equivalent to

$$2 x-(x+3)=4+\frac{x-3}{10}?$$

Give reasons for your answers.

(a) $2 x-x+3=4+\frac{x-3}{10}$

(b) $2 x-(x+3)=4+0.1 x-0.3$

(c) $x-3=3.7+0.1 x$

(d) $20 x-10(x+3)=4+x-3$

Different strains of a virus survive in the air for different time periods. For a strain that survives $t$ minutes, let $h(t)$ be the number of people infected (in thousands). The most common strain survives for $t_0$ minutes. What do the expressions tell you about the number of people infected?

$$\frac{h\left(2 t_0\right)}{h\left(t_0\right)}$$