Vikram is baking bread that calls for 3 3/4 cups of flour. If he makes only 1/4 of the recipe, how much flour will he need?

You're going on a 1211-mile trip, and your car gets about 29 miles per gallon. Gas prices along your route average $3.40. Estima

Vilka [71]

Answer:

Using the estimate:

The car has to go for 1,200 miles but it consumes a gallon of gasoline for every 30 miles. The number of gallons it will need is therefore:

= 1,200 / 30

= 40 gallons

Each gallon costs $3.00 so the total cost is:

= 40 * 3

= $120

Without using the estimate:

The car has to go for 1,211 miles but it consumes a gallon of gasoline for every 29 miles. The number of gallons it will need is therefore:

= 1,211 / 29

= 41.76 gallons

Each gallon costs $3.40 so the total cost is:

= 41.76 * 3.40

= $‭141.98

<em>Using the estimate provides a lower cost of gasoline for the trip. </em>

3 0

3 years ago

Prove the function f: R- {1} to R- {1} defined by f(x) = ((x+1)/(x-1))^3 is bijective.

Eduardwww [97]

Answer:

See explaination

Step-by-step explanation:

given f:R-\left \{ 1 \right \}\rightarrow R-\left \{ 1 \right \} defined by f(x)=\left ( \frac{x+1}{x-1} \right )^{3}

let f(x)=f(y)

\left ( \frac{x+1}{x-1} \right )^{3}=\left ( \frac{y+1}{y-1} \right )^{3}

taking cube roots on both sides , we get

\frac{x+1}{x-1} = \frac{y+1}{y-1}

\Rightarrow (x+1)(y-1)=(x-1)(y+1)

\Rightarrow xy-x+y-1=xy+x-y-1

\Rightarrow -x+y=x-y

\Rightarrow x+x=y+y

\Rightarrow 2x=2y

\Rightarrow x=y

Hence f is one - one

let y\in R, such that f(x)=\left ( \frac{x+1}{x-1} \right )^{3}=y

\Rightarrow \frac{x+1}{x-1} =\sqrt[3]{y}

\Rightarrow x+1=\sqrt[3]{y}\left ( x-1 \right )

\Rightarrow x+1=\sqrt[3]{y} x- \sqrt[3]{y}

\Rightarrow \sqrt[3]{y} x-x=1+ \sqrt[3]{y}

\Rightarrow x\left ( \sqrt[3]{y} -1 \right ) =1+ \sqrt[3]{y}

\Rightarrow x=\frac{\sqrt[3]{y}+1}{\sqrt[3]{y}-1}

for every y\in R-\left \{ 1 \right \}\exists x\in R-\left \{ 1 \right \} such that x=\frac{\sqrt[3]{y}+1}{\sqrt[3]{y}-1}

Hence f is onto

since f is both one -one and onto so it is a bijective

8 0

4 years ago

Choose the solution(s) of the following system of equations x2 + y2 = 6 x2 – y = 6

ElenaW [278]

<h2>Answer</h2>

$x=\sqrt{6}, y=0\\ x=-\sqrt{6} , y=0\\x=\sqrt{5} , y=-1\\x=-\sqrt{5} , y=-1$

Or as ordered pairs: $(\sqrt{6} ,0),(-\sqrt{6} ,0),(\sqrt{5} ,-1),(-\sqrt{5} ,-1)$

<h2>Explanation</h2>

Lets solve our system of equations step by step

$x^2+y^2=6$ equation (1)

$x^2-y=6$ equation (2)

1. Solve for $x^2$ in equation (2)

$x^2-y=6$

$x^2=6+y$ equation (3)

2. Replace equation (3) in equation (1) and solve for $y$

$x^2+y^2=6$

$6+y+y^2=6$

$y^2+y=0$

$y(y+1)=0$

$y=0$ or $y=-1$

3. Replace the values of $y$ in equation (3) and solve for $x$

- For $y=0$

$x^2=6+y$

$x^2=6$

$x=\sqrt{6}$ or $x=-\sqrt{6}$

- For $y=-1$

$x^2=6+y$

$x^2=6-1$

$x^2=5$

$x=\sqrt{5}$ or $x=-\sqrt{5}$

So, the solutions of our system of equation are:

$x=\sqrt{6}, y=0\\ x=-\sqrt{6} , y=0\\x=\sqrt{5} , y=-1\\x=-\sqrt{5} , y=-1$

6 0

3 years ago

Read 2 more answers

A random sample of 38 wheel chair users were asked whether they preferred cushion type A or B, and 28 of them preferred type A w

-BARSIC- [3]

Answer:

The statement that cushion A is twice as popular as cushion B cannot be verified

Step-by-step explanation:

From the question we are told that:

Sample size n=38

Type a size A $X_a=28$

Type a size B $X_b=10$

Generally the probability of choosing cushion A P(a) is mathematically given by

$P(a)=\frac{28}{38}$

$P(a)=0.73$

Generally the equation for A to be twice as popular as B is mathematically given by

$P(b)+2P(b)=3P$

Therefore Hypothesis

$Null H_0: p \leq \frac{2P}{3P} \\Altenative H_A:p>\frac{2P}{3P}$

Generally the equation normal approx of p value is mathematically given by

$z=\frac{x-np_0-0.5}{\sqrt{np_0(1-p_0)} }$

$z=\frac{28-(38*2/3)_0-0.5}{\sqrt{38*2/3*1/3} }$

$z=0.75$

Therefore from distribution table

$Pvalue=1-\theta (0.75)$

$Pvalue=0.227$

Therefore there is no sufficient evidence to disagree with the Null hypothesis $H_0$

Therefore the statement that cushion A is twice as popular as cushion B cannot be verified

7 0

3 years ago

Find the perimeter of rectangle PQRS with vertices P(0,0), Q(0,7), R(12,7) & S (12,0)

romanna [79]

P=7+7+12+12P=14+24P=38

See the attachment for diagram

8 0

3 years ago