One last time...algebra help please?

Question

Thanks for all the previous help, I need your help just one more time, and thanks to all ahead of time.
"The base of an isosceles triangle is 13 in. less than the length of the equal sides. If the perimeter is 47 in. find the length of each of the sides." This has to be in algebraic form and could you show the work please?

Answer 1

b=x-13
2x+b=47 or
3x-13=47
3x=60
x=20
b=7

Answer 2

In all these kinds of word problems, the first thing you need to do is assign variables to the values you want to find out. In this case they are "the length of each of the sides".

The definition of an isosceles triangle is that it has two sides the same length, so we want to find the base (b) and the other sides length (s)

b= length of base
s= length of other two sides

Now you just have to write algebra equations that say the same thing as the word equations in the problem.

base is 13 in less than the length of the equal sides

b=s-13

perimeter is 47

b+2s=47

Now we have the two equations and two unknowns and we just need to solve. there are several ways to solve but substitution would work well here. Just put what "b" is equal to in the first equation in place of "b" in the second equation and solve:

(s-13) + 2s = 47
s-13+2s=47
3s=60
s=20

remembering that b=s-13, b=20-13=7

s=20
b=7

and it checks

NOW, the problem was just a little confusing in that the wording of the first sentence does not make it clear whether the base is 13 less than EACH of the equal lengths or the TOTAL of the other lengths. So here is what happens if you do it the total way.

b=2s-13
2s+b=47
2s+(2s-13)=47
4s-13=47
4s=60
s=15
b=17

I think the first answer is more likely what the problem was intending.

Answer 3

let x= one of the equal sides
x-13+2x=47
combine like terms
3x-13=47
add 13 to each side
3x=60
divide each side by 3
x=20

the length of the base is 7
the lengths of the other two sides are 20

Answer 4

I hate math... i don't have the answer, but this site is great. I think you'll be able to figure it out.... when in doubt, google it!

http://mathworld.wolfram.com/IsoscelesTriangle.html

Answer 5

im srry thats really hard and im in honors math whoah hard problem! i wish u luck on finding the answer.......:)