00:01
So we have our diagram here and label everything.
00:09
So d, e, c, f, g, and b.
00:16
And we know that c -e -bisex angle dcf, which means that it cuts it into two concurrent parts.
00:24
So we know that angle e -c -d is concurrent angle f -c -e.
00:29
And then c -g also bisects angle f -c -b.
00:34
Which cuts it into two concurrent parts.
00:36
We know that these two angles here are concurrent.
00:40
And for 51, we know that angle d, c, e, equals 4x plus 15, and angle e, c .f equals 6x minus 5.
00:56
And since we know those are concurrent, we set them equal to each other.
00:59
So 4x plus 15 equals 6x minus 5.
01:05
Get x by itself...