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Angle H would be supplementary to the angle opposite it, which is 87. Therfore, angle H = 93.
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X is 12 and y is 15 because of 3,4,5 triangles
Answer:

Step-by-step explanation:
Given
, start by squaring both sides to work towards isolating
:

Recall
and
:

Isolate the radical:

Square both sides:

Expand using FOIL and
:

Move everything to one side to get a quadratic:

Solving using the quadratic formula:
A quadratic in
has real solutions
. In
, assign values:

Solving yields:

Only
works when plugged in the original equation. Therefore,
is extraneous and the only solution is 
42
let the smallest even number be x, than the four even numbers are x, x+2, x+4, x+6, their sum is 180
x+x+2+x+4+x+6=180
4x+12=180
4x=168
x=42
the smallest even number is 42.
The answer is g^-1= x^2/2 + 1/2