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The tape diagram represents the ratio of the time you spend tutoring to the time your friend spends tutoring. You tutor for 3 ho

Dafna11 [192]

Answer:

By a quick online search, i found two tape diagrams:

13) You: -

Friend: - -

So you have one block, and your friend has two.

We know that you work for 3 hours, this means that your only block must represent 3 hours.

And all the blocks represent the same amount of time, then each one of the two blocks of your friend also represents 3 hours.

Then in total, he tutored for 3 hours + 3 hours = 6 hours.

14) You: -

Friend: - - - - -

In this case, you still have only one block, but now your friend has 5.

Using the same reasoning as above, we can conclude that each block represents 3 hours, and your friend has 5 of them, this means that he tutored for:

5*3 hours = 15 hours

4 0

3 years ago

What are the solutions of the equation x6 + 6x3 + 5 = 0? Use factoring to solve.

lapo4ka [179]

Consider the equation $x^6+6x^3+5=0$ .

First, you can use the substitution $t=x^3$ , then $x^6=(x^3)^2=t^2$ and equation becomes $t^2+6t+5=0$ . This equation is quadratic, so

$D=6^2-4\cdot 5\cdot 1=36-20=16=4^2,\ \sqrt{D}=4,\\ \\ t_{1,2}=\dfrac{-6\pm 4}{2} =-5,-1$ .

Then you can factor this equation:

$(t+5)(t+1)=0$ .

Use the made substitution again:

$(x^3+5)(x^3+1)=0$ .

You have in each brackets the expression like $a^3+b^3$ that is equal to $(a+b)(a^2-ab+b^2)$ . Thus,

$x^3+5=(x+\sqrt[3]{5})(x^2-\sqrt[3]{5}x+\sqrt[3]{25}) ,\\x^3+1=(x+1)(x^2-x+1)$

and the equation is

$(x+\sqrt[3]{5})(x^2-\sqrt[3]{5}x+\sqrt[3]{25})(x+1)(x^2-x+1)=0$ .

Here $x_1=-\sqrt[3]{5} , x_2=-1$ and you can sheck whether quadratic trinomials have real roots:

1. $D_1=(-\sqrt[3]{5}) ^2-4\cdot \sqrt[3]{25}=\sqrt[3]{25} -4\sqrt[3]{25} =-3\sqrt[3]{25}$ .

2. $D_2=(-1)^2-4\cdot 1=1-4=-3$ .

This means that quadratic trinomials don't have real roots.

Answer: $x_1=-\sqrt[3]{5} , x_2=-1$

If you need complex roots, then

$x_{3,4}=\dfrac{\sqrt[3]{5}\pm i\sqrt{3\sqrt[3]{25}}}{2} ,\\ \\x_{5,6}=\dfrac{1\pm i\sqrt{3}}{2}$ .

6 0

3 years ago

A girl scout troop makes $1100 in two weekends of selling cookies. If they continued at this rate, how much money would they mak

baherus [9]

Answer:

$3850

Step-by-step explanation:

It is given that,

A girl scout troop makes $1100 in two weekends of selling cookies.

2 weekend = $1100

1 weekend = $550

For 7 weekend, we will multiply $550 by 7 as follows :

7 weekend = $550 × 7

= $3850

So, for 7 weekend she will need $3850.

6 0

3 years ago

During a fundraiser, Ms. Dawson’s class raised $560, which is 25% more than Mr. Casey’s class raised. How much money did Mr. Cas

evablogger [386]

Answer:

$420

Step-by-step explanation:

To work this out you would need to find the 25% decrease of 560. To do this you would first divide 25 by 100, which gives you 0.25. Then you would minus 0.25 from 1, which gives you 0.75. This is because when finding percentage decreases you would first have to convert it into a decimal. Then you would have to minus it from 1 , to make sure that it will be a 25% decrease not a 75% decrease. Then you would multiply 560 by 0.75, which gives you 420.

1) Divide 25 by 100.

$25/100=0.25$