<span>The answers to this problem are:<span>(<span>±5</span></span>√3/8,±5/8)<span>Here is the solution:
Step 1: <span><span><span>x2</span>+<span>y2</span>=<span>2516</span>[2]</span><span><span>x2</span>+<span>y2</span>=<span>2516</span>[2]</span></span>
Step 2: Substitute:<span>
</span><span><span>8<span><span>(<span>25/16</span>)^</span>2</span>=25(<span>x^2</span>−<span>y^2</span>)
</span><span>8<span><span>(<span>25/16</span>)^</span>2</span>=25(<span>x^2</span>−<span>y^2</span>)</span></span>
</span><span>x^2</span>−<span>y^2</span>=<span>25/32</span><span>.
Add [2] and [3]:<span>
</span><span>2<span>x^2</span>=<span>75/32
</span><span>x^2</span>=<span>75/74</span></span>
<span>x=±5</span></span>√3/8<span>
Substitute into [2]:<span>
</span><span><span>75/64</span>+<span>y^2</span>=<span>50/32
</span><span>y^2</span>=<span>25/64</span></span>
<span>y=±<span>5/8</span></span>
</span>
</span>
Answer: 
Step-by-step explanation:
You can observe in the figure two parallel lines that are intersected by a transversal and several angles are formed.
The angles m∠3 and m∠6 are located inside the parallel lines and on one side of the transversal, this angles are known as "Consecutive interior angles" and they are supplementary (which means that they add up 180°).
Therefore, you know that:

So you can substitute m∠3=130° and solve for m∠6. Then you get:

Answer:
77.
Proved
78.
Proved
79.
Proved.
80.
Proved.
Step-by-step explanation:
77. Left hand side
=
=
=
{Since we know,
}
=
= Right hand side (Proved)
78. Left hand side
=
=
{Since
}
=
= Right hand side (Proved)
79. Left hand side
=
=
{Since
}
=
= Right hand side
80. Left hand side
=
=
{Since
}
=
=
= Right hand side. (Proved)
So hmmm let's do the left-hand-side first

now, let's do the right-hand-side then