(15 POINTS!) The slope of the line passing through the points (7, 5) and (21, 15) is

5/7
7/5
5
7

Another line with a slope that is one-third that of the slope you just calculated passes through the origin and the point

3, 5
3, 7
21, 5
21, 7

1) 5/7

2) (21, 5)

Step-by-step explanation:

1) The slope of the line passing through the points (7, 5) and (21, 15) is

because slope is (difference of y)/(difference of x)

the first option is correct

2) 1/3 of 5/7 is 5/21.

The line will be in the form of

y = 5/21 x + b where b is the y-intercept.

Find the complete equation by plugging in (0,0) since it passes thorugh the origin.

0 = 5/21 (0) +b

0=0+b

b=0

The equation: y=5/21 x

let's check each option by plugging in.

y= 5/21 (3)= 5/7

y is not 5 but 5/7

y= 5/21 (3)= 5/7

y is not 7 but 5/7

y= 5/21 (21) = 5

y is 5, which matches with the answer choice!!!

y= 5/21 (21) = 5

y is 5, not 7.

The third option is correct

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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