Question

The polygons are similar, but not necessarily drawn to scale. Find the vale of x.
(Will post picture of the polygon in comments)
Please help!!!

Answer 1

the sides of the similar figures will be in equal ratios

Answer 2

for example

16 to 12
will be the same as
(x-1) to 6

Answer 3

Yeah. So its
6 ; 12
(x-1) ; 6
(y + 1) ; 21
32 ; 24

Answer 4

\[\frac{ 16 }{ 12 }=\frac{ x-1 }{ 6 }\]

Answer 5

Then I would do
16 (6) = x - 1 (12) right?

Answer 6

all those will be the same fraction,
32/24 = 1.3333
16/12 = 1.3333
(x-1)/6 = 1.3333

all the sides will be 1.333 times as a scale factor

Answer 7

so you can set any of the two fractions equal

Answer 8

right, you just had the grouping off a little

16*6 = 12*(x-1)

distribute the 12 into the (x-1) first

Answer 9

so it would end up
96 = 12x - 12

Answer 10

correct

Answer 11

and from there it would be
108 = 12x
then
9 = x
Correct?

Answer 12

yep

Answer 13

what equation would you set up to find out what y is?

Answer 14

Would it be 32/24 = y+1/21?

Answer 15

yep, just when you are typing equations, group the numerator (y+1)/21, the way you typed it turns into
\[y + \frac{ 1 }{ 21 }\]

Answer 16

Oh alright. Do you think you could check my work on a couple more? I just want to make sure I'm doing them correctly.

Answer 17

sure

Answer 18

ok here it is:
What is the solution to the proportion?
\[\frac{ 3y - 8 }{ 12 } = \frac{ y }{ 5 }\]
I got a little confused on this one. I ended up with:
5 (3y-8) = 12y
15y-40 = 12y
-40= -3y
13.33 = y

Answer 19

right, 40/3

Answer 20

or 13.33 if you want an approximate answer

Answer 21

so y is 40/3?

Answer 22

yes, you can always test and see by putting that in for y in the original equation, and check if both sides are the same number.

Answer 23

32/12 = 2.66666
40/15 = 2.6666 same

Answer 24

Alright alright. Only one more. Sorry to bother you.
Given the proportion \[\frac{ a }{ b } = \frac{ 8 }{ 15 }\] what ratio completes the equivalent proportion \[\frac{ a }{ 8 }\]?

Answer 25

I ended up with a = 1.1

Answer 26

\[\frac{ a }{ b } = \frac{ 8 }{ 15 }\]

15a = 8b
\[\frac{ a }{ 8 } = \frac{ b }{ 15 }\]

Answer 27

you cant solve for a value of a, there are 2 variables in 1 equation., you can solve like above.
a/8 = b/15

a in terms of b

Answer 28

Oh ok I see. I thought you would replace a/b with a/8 so it would be set up like:
a/8 = 8/15

Answer 29

i dont think so, just solve for a/8 from what was given

Answer 30

Alright. Thank you so much! I really appreciate the help!!

Answer 31

no problem, anytime