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3 years ago

9

Your cousin is 8 years older than your brother. Three years ago, your cousin was twice as old as your brother. How old is your c

ousin now? How old is your brother now?

1 answer:

ValentinkaMS [17]3 years ago

8 0

Answer:

19 and 11

Step-by-step explanation:

You might be interested in

18% of the the students at a school are in year 8 and 16% of the students are in year 9. If the school has 126 tera 8 students,

yarga [219]

Answer:

112

Step-by-step explanation:

The general form of all percentage questions is: the chunk= (some percentage) (of the whole), or c=p*w

We know that 18% of students are 8th grade and that is 126 students, so p = 0.18 and c=126 (126 students are 18% of the whole school)

126 = (0.18)w, divide both sides by 0.18

126/(0.18) = w = 700

9th graders are 16% of the school or 16% of 700 students

c = (0.16) 700 = 112 students

5 0

3 years ago

The points A(1, 4), B(5,1) lie on a circle. The line segment AB is a chord. Find the equation of a diameter of the circle.

tangare [24]

Check the picture below.

well, we want only the equation of the diametrical line, now, the diameter can touch the chord at any several angles, as well at a right-angle.

bearing in mind that <u>perpendicular lines have negative reciprocal</u> slopes, hmm let's find firstly the slope of AB, and the negative reciprocal of that will be the slope of the diameter, that is passing through the midpoint of AB.

$\bf A(\stackrel{x_1}{1}~,~\stackrel{y_1}{4})\qquad B(\stackrel{x_2}{5}~,~\stackrel{y_2}{1}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{1}-\stackrel{y1}{4}}}{\underset{run} {\underset{x_2}{5}-\underset{x_1}{1}}}\implies \cfrac{-3}{4} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{slope of AB}}{-\cfrac{3}{4}}\qquad \qquad \qquad \stackrel{\textit{\underline{negative reciprocal} and slope of the diameter}}{\cfrac{4}{3}}$

so, it passes through the midpoint of AB,

$\bf ~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ A(\stackrel{x_1}{1}~,~\stackrel{y_1}{4})\qquad B(\stackrel{x_2}{5}~,~\stackrel{y_2}{1}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left( \cfrac{5+1}{2}~~,~~\cfrac{1+4}{2} \right)\implies \left(3~~,~~\cfrac{5}{2} \right)$

so, we're really looking for the equation of a line whose slope is 4/3 and runs through (3 , 5/2)

$\bf (\stackrel{x_1}{3}~,~\stackrel{y_1}{\frac{5}{2}}) \stackrel{slope}{m}\implies \cfrac{4}{3} \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{\cfrac{5}{2}}=\stackrel{m}{\cfrac{4}{3}}(x-\stackrel{x_1}{3})\implies y-\cfrac{5}{2}=\cfrac{4}{3}x-4 \\\\\\ y=\cfrac{4}{3}x-4+\cfrac{5}{2}\implies y=\cfrac{4}{3}x-\cfrac{3}{2}$

4 0

3 years ago

The diagram shows the blueprint of a vegetable garden. All dimensions are given in yards.

Delicious77 [7]

Answer:

D

Step-by-step explanation:

i saw another brainly and he seemed to be correct and i got it right :)!

6 0

2 years ago

1.2, 3, 7.5, 18.75, ...<br><br> Which formula can be used to describe the sequence?

Nady [450]

Answer:

The formula is:

$a_n=1.2(\frac{5}{2})^{n-1}$

Step-by-step explanation:

The geometric sequences are those in which the division between the terms $a_{n + 1}$ and $a_n$ of the sequence are equal to a constant common reason called "r"

The geometrics secencias have the following form:

$a_n=a_1(r)^{n-1}$

Where $a_1$ is the first term of the sequence

In this sequence we have the following terms

1.2, 3, 7.5, 18.75

Then notice that:

$\frac{3}{1.2}=\frac{5}{2}\\\\\frac{7.5}{3}=\frac{5}{2}\\\\\frac{18.75}{7.5}=\frac{5}{2}$

Then:

$r=\frac{5}{2}$ and $a_1=1.2$

Finally the formula is:

$a_n=1.2(\frac{5}{2})^{n-1}$

5 0

3 years ago

Read 2 more answers

Question is in the picture

irakobra [83]

Answer:

49.4 (rounded to the nearest tenth)

Step-by-step explanation:

You need to use the Pythagorean theorem -> $a^{2} + b^{2} = c^{2}$ -> $c^{2}$ is the hypotenuse

$a^{2} + b^{2} = c^{2}$

$(7x + 7)^{2}$ + $5x$ = $c^{2}$

(7x $7)^{2}$ + (5x7) = $c^{2}$

$49^{2}$ + 35 = $c^{2}$

2436 = $c^{2}$

$\sqrt{2436}$ = c

c = 49.355850717

c = 49.4 (round to the nearest tenth)

hope this helps, sorry if it is not right

4 0

2 years ago