AB = 2x+7
BC = 3x+5
AC = 5x-4
The perimeter is 58.
Find me x and AB.
2007-10-08 09:01:55 · 9 answers · asked by Yahoo! King 1 in Science & Mathematics ➔ Mathematics
perimeter is 58 ; therefore add all the sides to equal 58
2x+7+3x+5+5x-4=58
10x+8=58
10x=50
x=5, and plug in 5 into the equation AB
2(5)+7=17; therefore, AB=17, and x=5
2007-10-08 09:06:16 · answer #1 · answered by icemoon 2 · 0⤊ 0⤋
Perimeter is the sum of the sides of a shape. So in this case the perimeter, 58 = length(AB) + length(BC) + length(AC)
Replacing the equations provided gives us:
58 = (2x+7) + (3x+5) + (5x-4)
We can quickly combine th elike terms on the right side of the equation to provide
58 = (2x + 3x + 5x) + (7 + 5 - 4)
and further simplify to
58 = 10x +8
Subtracting 8 from both sides of the equation gives us:
50=10 x
Dividing both sides by 10 gives us:
x=5
To obtain the length of segment AB we plug our x value back into the equation for segment AB.
2 x (5) + 7 = 17
2007-10-08 09:19:23 · answer #2 · answered by Andrew K 6 · 0⤊ 0⤋
If those are the three side lengths, and you're told the perimeter is 58, then add up all the expressions and set the sum equal to 58:
(2x+7) + (3x+5) + (5x-4) = 58
Solve this for x, and then use x to find the length of AB, 2x+7.
2007-10-08 09:06:36 · answer #3 · answered by Anonymous · 0⤊ 0⤋
(2x + 7) + (3x + 5) + (5x - 4) = 58 - remove brackets.#
2x + 7 + 3x + 5 + 5x - 4 = 58 - collect like terms
10x + 8 = 58 - subtract 8 from both sides
10x = 58 - 8 = 50 - divide 10 into both sides
x = 50/10 = 5
x = 5
AB = 2x + 7
AB = 2(5) + 7
AB = 10 + 7
AB =17
2007-10-08 09:08:43 · answer #4 · answered by lenpol7 7 · 0⤊ 0⤋
58=2x+7+3x+5+5x-4
or 58=10x+8
or 58-8=10x
or 10x=50
or x=50/10=5
& AB=2x+7=2*5+7
or AB=17 & x=5 ans
2007-10-08 09:08:29 · answer #5 · answered by MAHAANIM07 4 · 0⤊ 0⤋
Sum all three of the above expressions and put them equal to 58.
(2X+7) + (3X+5) + (5X-4) =58
10X + 8 = 58
I'll let you get it from here. Once you get X you can substitute it in 2X+7 to figure out what AB is.
2007-10-08 09:07:33 · answer #6 · answered by CHILL 1 · 0⤊ 0⤋
the perimeter is all of the sides added up together so:
AB+BC+AC=58
(2x+7)+(3x+5)+(5x-4)=58
2x+7+3x+5+5x-4=58
10x+8=58
10x=50
x=5
AB= 2x+7
AB= 2(5)+7
AB=17
2007-10-08 09:07:33 · answer #7 · answered by awesomeAnonymous 1 · 0⤊ 0⤋
perimeter=AB+BC+AC
58=2x+7+3x+5+5x-4
58=10x+8
58-8=10x
50=10x
x=50/10=5
AB=2*5+7=10+7=17
2007-10-08 09:07:49 · answer #8 · answered by Anonymous · 0⤊ 0⤋
do your own your! it's not that hard.
2007-10-08 09:09:58 · answer #9 · answered by roche065 3 · 0⤊ 0⤋