Answer:
AC = 30
Step-by-step explanation:
Start with:

Combine like terms.

Subtract
from both sides of the equation.

Subtract
from both sides of the equation.

Then, substitute
for
in 

Multiply.

Finally, add.

Answer:
24
Step-by-step explanation:
just multiply 2 on both sides
Answer:
"In word" as in word form?
3/4 = three fourths
1/5 = one fifth
3/4 = three fourths (again?)
1 3/5 = one and three fifths
I would use the pythagorean theorem to find the lengths of each side. a² + b² = c².
Side AB is one we're looking for. If you make other right triangle with that same side you can see that one length is 4 and the other is 3. So, 4² + 3² = c² → 25 = c² → 5 = c. Side AB is length 5.
Side AC is another. Do the same with that side and you get that one length is 4 and the other is 3. (This is the same one as above) so side AC is length 5.
Side BC is the last one. One of the lengths is 1 and the other is 1 → 1² + 1² = c² → 2 = c² → 1.414213562 = c so side BC is approximately length 1.41.
Add each length up and you get a perimeter of roughly 11.4