You need to explain to us what to do or else nobody will understand what your trying to ask for.
<span><span><span>3x</span>+<span>4y</span></span>=8
</span>Add -4y to both sides
<span><span><span><span>3x</span>+<span>4y</span></span>+<span>−<span>4y</span></span></span>=<span>8+<span>−<span>4y</span></span></span></span><span><span>3x</span>=<span><span>−<span>4y</span></span>+8
</span></span>Then you divide both sides by 3
<span><span><span>3x/</span>3</span>=<span><span><span>−<span>4y</span></span>+8/</span>3</span></span><span>x=<span><span><span><span>−4/</span>3</span>y</span>+<span>8/3
</span></span></span>And your answer is ...
<span>x=<span><span><span><span>−4/</span>3</span>y</span>+<span>8/<span>3</span></span></span></span>
Answer: should be A: 1.75 hours
Step-by-step explanation: divide 28/16 to give you 7/4, then you should turn this into a decimal which gives you 1.75
Cos <span>2</span><span>x </span><span>= </span><span>2</span><span>cos^</span><span>2</span><span>(</span><span>x</span><span>) </span><span>− </span><span>1</span>
2<span>cos^</span><span>2 </span><span>(</span><span>x</span><span>) </span><span>− </span><span>1 </span><span>− </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>≡ </span><span>2</span><span>cos^</span><span>2</span><span>(</span><span>x</span><span>) </span><span>− </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>− </span><span>1</span>
Let <span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>y</span>
2<span>y^</span><span>2 </span><span>− </span><span>y </span><span>− </span><span>1
</span><span>(</span><span>2</span><span>y </span><span>+ </span><span>1</span><span>) </span><span>(</span><span>y </span><span>− </span><span>1</span><span>) </span>y <span>= </span><span>−</span><span>1/2
</span><span>y </span><span>= </span><span>1</span>
y <span>= </span><span>cos</span><span>(</span><span>x)</span>
∴ <span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>−</span><span>1/</span><span>2 ; </span><span>cos</span><span>(</span><span>x</span><span>) </span><span>= </span><span>1</span>
x <span>= </span><span>2/</span><span>3 </span><span>π ;</span><span> </span><span>x </span><span>= </span><span>0</span>
solutions;x <span>= </span><span>2/</span><span>3 </span><span>π</span><span>, </span><span>x </span><span>= </span><span>0</span><span>, </span><span>x </span><span>= </span><span>4/</span><span>3 </span><span>π</span><span>, </span><span>x </span><span>= </span><span>2</span><span>π</span>
Answer:

Step-by-step explanation:
The slope-intercept form of the equation is y=mx+b where m is the slope and b is the y intercept. We know so far, that the slope is -8. We plug that in for m.

Now, we need to find the y-intercept. The question gives us the point (-7,-5). We plug in -7 for x, and -5 for y.

Then, we solve.

Subtract 56 from both sides.

Finally, we get this equation:
y=-8x-61