<span>8x + 8y = -48
-------------------------
Plug in -8 for x
(8) (-8) + 8y = -48
-------------------------------
Simplify
</span><span><span><span>(8) </span><span>(<span>−8</span>) </span></span>+ <span>8y </span></span>= <span>−<span>48
</span></span><span><span>−64 </span>+ <span>8y </span></span>= <span>−<span>48
</span></span><span><span>8y </span>− 64 </span>= <span>−<span>48
</span></span>-----------------------------------------
Add 64 to each side
<span><span><span>8y </span>− 64 </span>+ 64 </span>= <span><span>−48 </span>+ 64
</span><span>8y </span>= <span>16
</span>---------------------------------------------------
Finally, divide each side by 8
8y ÷ 8 = 16 ÷ 8
y = <span>2
</span>----------------------------------------------------------------
y = 2 is your answer
The answer is option "3, 40".
<span>m∠cab = 2x
m∠acb = x + 30
m∠cbd = 5x − 50
Now,
</span>m∠cab + m∠acb = m∠cbd
2x+x+30 = 5x-50
2x+x-5x = -50-30
-2x = -80
x = 40
This is the answer -1/6, -3, 1/6, .5,
75/3=25 miles per hour
That's your answer.