Answer:
Part 1) 
Part 2) 
Step-by-step explanation:
The picture of the question in the attached figure
Part 1
Find the length side AB
we know that
----> by SOH (opposite side divided by the hypotenuse)
substitute the given values

solve for AB

Part 2
Find the length side AC
we know that
----> by TOA (opposite side divided by the adjacent side)
substitute the given values

solve for AC

The first one and the last one
I can only assume that you meant, "Solve for x:"
Apply the exponent 3/2 to both sides of this equation. The result will be
3/2
343 = x/6.
Multiplying both sides by 6 isolates x:
3/2
6*343 = x Since 7^3 = 343, the expression for x
can be rewritten as
3/2
6*(7^3) = x which can be further simplified, as follows:
x = 6^(3/2)*7^(9/2), or:
x = 6^(3/2)*7^(8/2)*√7, or
x = 6^(3/2)*7^4*√7
So 1st make it equal to zero
x^2+4x-12
(x+6)(x-2)
so
x=-6 or 2 is the correct answer