Hey there! :D
We need to use proportions to figure this out.
Think of it as a comparison of the whole triangle, and then the smaller triangle on top. Make sure to be careful when you do this on your own. Try to align the sides with each other, and find the right proportions.
[tex] \frac{8}{8+x} = \frac{10}{10+x+2} [/tex]
Simplify.
[tex] \frac{8}{8+x} = \frac{10}{12+x} [/tex]
Cross multiply.
[tex]8(12+x)= 10(8+x) [/tex]
Distribute.
[tex]96+8x= 80+10x[/tex]
Subtract 8x on both sides.
[tex]96= 80+2x[/tex]
Subtract 80 on both sides.
[tex]16= 2x[/tex]
Divide both sides by 2.
[tex]x=8[/tex]
I hope this helps!
~kaikers
