English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

in rectangle ABCD

AB= 2x + 6

BC= 5y

CD= 7y

DA= 2x+2

I have tried and I know that opposite sides are congruent. but when i do that i don't get an anzwer.

PLEASe Help1

2006-07-02 04:56:08 · 12 answers · asked by Matt21 3 in Science & Mathematics Mathematics

12 answers

2x+6 = 7y
-(2x+2 = 5y)
-------------------
4 = 2y
y = 2

2x+6 = 14
2x = 8
x = 4

2006-07-02 05:01:24 · answer #1 · answered by lenny 7 · 1 0

Since this is a rectangle, this boils down to a "two equations / two unknowns" problem.

1) AB=CD so 2x + 6 = 7y
2) BC=DA so 2x + 2 = 5y

Solve the first equation for x (in terms of y):
x = (7y - 6)/2

Now plug this value for x into the second equation:
2((7y - 6)/2) + 2 = 5y

Then solve for the value of y:
(7y - 6) + 2 = 5y
2y = 4
y=2

With y=2, take either equation 1 or 2 above and solve for x:
1) 2x + 6 = 7y
2x + 6 = 14
2x = 8
x = 4

Is this correct? Try your values for x and y in the second equation:
2) 2x + 2 = 5y
2(4) + 2 = 5(2)
10 = 10, which is indeed true, so there is your answer (after a quick edit to my original post! *doh*!)

voila!

2006-07-02 05:14:05 · answer #2 · answered by bdyscr33t 2 · 0 0

AB+BC = CD+AD
2x+6+5y = 7y+2x+2
(the 2x cancel each other out, and the 2 reduces the 6 to 4 therefore)
4+5y=7y
4=2y
Therefore y =2

Now substitute the above solution into the following equation:

AB = CD
2x+6 = 7y
2x+6 = 14
2x = 8
Therefore x = 4


Solution to above is:
y = 2
x = 4

2006-07-02 10:05:38 · answer #3 · answered by sam_keane_uk 3 · 0 0

I see that this rectangle is parallel with the axes...

It is a rectangle with base 4 and height (2x+6 - 7y).

Since this rectangle has base 4, then 7y - 5y, or the other way around, must also equal 4. Therefore, y = ±2.

Now, 2x+6 = 7y, so 2x+6 = ±14.

Case 1: 2x+6 = 14
2x = 8
x = 4

Case 2: 2x+6 = -14
2x = -20
x = -10

2006-07-02 05:17:56 · answer #4 · answered by Anonymous · 0 0

well, as opposite sides are congruent, AB == CD or 2x + 6 = 7y, and BC == AD or 5y = 2x + 2.

so 5y + 4 = 2x + 2 + 4 = 2x + 6 = 7y

so y = 2, and then substituting that back in to 5y = 2x + 2 you get 10 = 2x + 2 => x = 4

Where's the problem?

2006-07-02 05:03:44 · answer #5 · answered by Stephan B 5 · 0 0

first, draw a picture. look at it. you will see that from the diagram, 2x+2=5y and 2x+6=7y. obviously then y=2, because 2y is a difference of 4. next, put the real numbers on the y sides of the rectangle and you should quickly see that x=4. then do all the math to convince your teacher you understand it.

2006-07-02 05:45:15 · answer #6 · answered by Anonymous · 0 0

If AB=DC and AD=BC, then AB=BC= CD+AD
2x+6+5y = 7y+2x+2
We then subtract 2x+2 from each side and 5y from each side to get:
4=2y
Divide by 2 to get y=2
We can then subsitute 2 for y in 7y = 2x+6
7 (2)=2x+6
14=2x+6
solve for x and you'll find X=4

2006-07-02 05:29:18 · answer #7 · answered by jas2012 1 · 0 0

the main nicely-known element this equation is attempting to enhance, i think of, is how order of operations works so we are going to take it in steps. a million. replace 8 for X on your equation: y = (8*2 / 4) - 2. Now remedy for y. 2. keep in mind which you do the stuff interior parenthesis first. With the stuff interior the parenthesis carry out multiplication and branch first, going from left to good. So do 8 * 2 first that's sixteen. Then divide sixteen via 4 that's 4. This leaves you with y = 4 - 2 and ... 3. y = 2. you could verify your answer via substituting 2 for y on your unique equation: 2 = (8*2/4)-2. Do the mathematics and you will discover that 2 = 2 that's real and consequently proves your answer is real. reliable luck, Amanda

2016-11-01 02:20:14 · answer #8 · answered by ? 4 · 0 0

AB=CD
2x+6=7y

BC=DA
5y=2x+2

Hence
2x+6=7/5 * (2x+2)
Multiply by 5 and use distributive property
10x+30=14x+14
14x-10x=30-14
4x=16
x=16/4=4

x=4

5y=2*4+2
5y=10
y=10/5=2

y=2

2006-07-02 05:19:26 · answer #9 · answered by iyiogrenci 6 · 0 0

well, that's the key point
AB=DC
2x+6=7y 1)

AD=BC
2x+2=5y 2)

FROM 1) AND 2)

2x+6=7y
2x+2=5y

subtract one from another

2x+6=7y
-(2x+2=5y)
-------------------
2x+6=7y
-2x-2=-5y
-----------------
4= 2y
4/2= y
2=y
put the value of y in 1)
2x+6=7y
2x+6=7*2
2x+6=14
2x=14-6
2x=8
x=8/2
x=4
now check it by putting the value of x and y on their repective places. if AB=DC and AD=BC
then your answer is correct otherwise u did something wrong somewhere

2006-07-02 06:03:32 · answer #10 · answered by priya b 2 · 0 0

ok!
AB=CD (opposite sides of a rectangle)
=> 2x + 6 = 7y
=> 2x - 7y = -6 --------------------(1)
also, AD = BC
=> 2x + 2 = 5y
=> 2x - 5y = -2 ----------------------(2)
therefore, subtracting (2) from (1)
2x - 7y = -6
2x - 5y = -2
(-) (+) (+)
we get, 0 - 2y = - 4
therefore y = 2
now put value of y in (1)
2x - (2) (7) = -6
2x - 14 = -6
2x = 8
x = 4
therefore,
x = 4
& y = 2

2006-07-02 07:11:08 · answer #11 · answered by pui27 3 · 0 0

fedest.com, questions and answers