9.9 is the answer..............
<span>The sum of angles CAD and DAB is 180 degrees. This is because they are all on a straight line (because points CAB are colinear) and angles on a straight line add up to 180 degrees.</span>
30 tens + 2 ones = 32
Hope I helped :P
So 8x+4+4x+8=15x-9
Combine like terms.
12x+12=15x-9
Add 9 to both sides.
12x+21=15x
Subtract 12 from both sides.
21=3x
Divide both sides by 3.
x=7
Now plug in 7 for x in 8x+4.
8(7)+4
56+4
=60
15) x=31/10
16)x=2
17)x=16/3
18)x=-2
19)2.5 hours
20) 32 hours