Would you say that Johnson's tone is the same in "On Spring" and “on Idleness"? Support your answer.

Everyone’s skin contains about the same number of melanocytes, even though people have many different skin colors. How is this possible?

Solve using Gauss-Jordan elimination.

$$\begin{aligned} 2 x_{1}+4 x_{2}-2 x_{3} &=2 \\-3 x_{1}-6 x_{2}+3 x_{3} &=-3 \end{aligned}$$

Write the series in summation notation.

$$1 + \frac { 1 } { 4 } + \frac { 1 } { 9 } + \frac { 1 } { 16 } + \frac { 1 } { 25 }$$

For any rectangle WXYZ, decide whether the statement is always or sometimes true. Draw a diagram and explain your reasoning. W̅X̅ ≅ Y̅Z̅

Is the product less than or greater than the factors? Explain.

Find the absolute extrema of the function on the region. $f(x, y)=x^{2}+y^{2}-2 x-4 y$, region bounded by y=x, y=3 and x=0

What kinds of problems might running away from home lead to?

Each of the matrices is in reduced echelon form. Write the system of equations represented by each and find the solution, if possible.

$$\left[\begin{array}{rrrr|r}{1} & {0} & {0} & {3} & {0} \\ {0} & {1} & {0} & {-2} & {0} \\ {0} & {0} & {1} & {7} & {0} \\ {0} & {0} & {0} & {0} & {0}\end{array}\right]$$

Two students are passing a ball back and forth, allowing it to bounce once between them. If one student bounce-passes the ball from a height of 1.4 m and it bounces 3 m away from the student, where should the second student stand to catch the ball at a height of 1.2 m ? Assume the path of the ball is linear over this short distance.

Find $\frac{d^{2} y}{d x^{2}}$.

$$y=x^{5}-5 x^{4}+7 x^{3}+17$$

Describe the control of blood pressure.

A $50-\mathrm{kg}$ mountain climber moves $30 \mathrm{m}$ up a vertical slope. If the muscles in her body convert chemical energy into gravita tional potential energy with an efficiency of no more than $5 \%$, what is the chemical energy used to climb the slope? (a) 7 kcal (b) 3000 J (c) 70 kcal (d) 300,000 J

Determine whether each relation $R$ defined on the collection of all nonemtpy subsets of real numbers is reflexive, symmetric, antisymmetric, transitive, and/or a partial order. $(A,B)\in R$ if for every $a\in A$ and $\varepsilon\gt 0$, there exists $b\in B$ with $|a-b|\lt \varepsilon$.