In order to solve this problem, we must solve an equation.
First, we need to define our unknown.
Let's call our number "n".
So, the sum of the number and 6 is the same as saying n+6
Then we need to multiply it by 2 (since it's twice the sum)
2(n+6)
This whole thing is equal to three times of the difference of the number and 8
n-8 is equal to the difference between the number and 8, then we need to multiply it by three.
3(n-8)
now, we set both sides equal and solve
The number is 36
Answer:
In reality, the 5's go on forever, but we have to round off somewhere.
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Explanation:
Break up the triangles as your teacher recommends. See the diagram below as to what I mean.
The smaller triangle has A = 8 as the horizontal side, and B = x as the vertical side
The larger triangle has C = 10+8 = 18 as the horizontal aside, and D = 8 as the vertical side.
We can form the proportion A/C = B/D.
A/C connects the horizontal sides (small/large) while B/D has the vertical sides tied together. The order of division is the same small over large. You could do large over small, but make sure you keep both sides consistent.
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Let's solve for x
A/C = B/D
8/18 = x/8
8*8 = 18*x .... cross multiply
64 = 18x
18x = 64
x = 64/18 .... divide both sides by 18
x = 32/9 exactly in fraction form
x = 3.556 approximately in decimal form
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Another proportion you can solve is A/B = C/D and you should get the same x value. It's the same as A/C = B/D because the B and C swap places. There are many other approaches you could take using different proportions.
