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beks73 [17]
3 years ago
5

The sum of the areas of two circles is 80 pi square meters find the length of the radius of a radius of each circle if one of th

em is twice the orher
Mathematics
1 answer:
Leno4ka [110]3 years ago
3 0
Let x=small circle
2x = bigger circle

πx^2 + π(2x)^2 = 80π
x^2 + 4x^2 = 80
5x^2 = 80
x^2 = 16
x = +/- 4
but we need the positive one because there's no negative measurement so
the answers are:
4m and 8m
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Please help me with number six
Tpy6a [65]

w = 2x = 2( \frac{y}{3}) \\ v = 2w = 2 \times 2( \frac{y}{3} ) \\ v + w  + x + y = 180 \\  \frac{4}{3} y +  \frac{2}{3} y +  \frac{y}{3}  + y = 180 \\ y( \frac{4}{3}  +  \frac{2}{3}  +  \frac{1}{3}  + 1) = 180 \\ y =  \frac{180}{()}
5 0
3 years ago
What’s the answer to this question
Makovka662 [10]
25......................
5 0
3 years ago
Read 2 more answers
My watch is 5 minutes slow, but i think it is 3 minutes fast. I arrive 'on time' according to my calculations to catch the 1:15
faltersainse [42]
1:15 pm + 5 minutes =1:20 PM  You add 5 minutes because your watch is slow then subtract 3 minutes because you thought the watch was 3 minutes fast. real time is 1:17 PM
 1:20 pm  - 3 minutes = 1:17 PM
4 0
3 years ago
Wangari plants trees at a constant rate of 1212 trees every 33 hours. Write an equation that relates pp, the number of trees Wan
igor_vitrenko [27]

Answer:

p=4h    

Step-by-step explanation:

Let p be the number of trees Wangari plants, and h  be the time she spends planting them in hours.

We have been given that Wangari plants trees at a constant rate of 12 trees every 3 hours.    

Let us find number of trees planted in 1 hour by dividing 12 by 3.

\text{Number of trees planted in 1 hour}=\frac{12\text{ plants}}{3\text{ hour}}

\text{Number of trees planted in 1 hour}=4\frac{\text{ plants}}{\text{ hour}}

We can represent this information as: p=4h

Therefore, the equation p=4h relates the number of trees (p) Wangari plants, and the time (h) she spends planting them in hours.

3 0
3 years ago
Read 2 more answers
Which is not an equation of the line going through (6, 7) and (2, –1)?
garri49 [273]
Answer - D.

you basically find the equation of the line first and eliminate the wrong answers...

Strategy:  before u do any of this, label your coordinates as (X1,Y1) and (X2,Y2) and u can choose any of ur points to be as x1 or x2 or y1 or y1...
basically, I'll choose (6,7) as (x1,y1) and (2,-1) as (x2,y2). SO,

First you have to  find the gradient (m) of the line.
  you do this by using the formula m = Y2-Y1 / X2-X1 (where '/' is division sign) ....
Put the numbers in their respective places and your gradient will be 2x. we put the x after our number to represent it as a gradient as the straight line formula is y = mx+c and you've found the m.
NOW.
use the formula Y-Y1=m(x-x1) to find the equation of the line.Again u can use any Y1 and X1 here but remember your m is 2

replace the digits and solve...Hopefully you'll get sth like this if you use the points (6,7):
Y-7 = 2(x-6) ....
y=2x-12+7...
Y=2x-5! <<<< this is your straight line equation!
Now all u gotta do is rearrange all your options into y = mx+c.
D. is incorrect as it gives us y=2x+5 and not y = 2x-5 unlike the others 
 

Hope you get it!




7 0
3 years ago
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