9514 1404 393
Answer:
x = 3.6
Step-by-step explanation:
The angle bisector divides the segments proportionally. This means they satisfy ...
bottom segment / side segment = x/6 = (6-x)/4
Multiplying by 12 gives ...
2x = 3(6 -x)
2x = 18 -3x . . . . . eliminate parentheses
5x = 18 . . . . . . . . add 3x
x = 3.6 . . . . . . . . . divide by 5
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Alternate solution
I like to try to work these mentally. The total of side lengths is 10, so the total base length (6) is 6/10 = 0.6 times that. Then x will be 0.6 times the left side length: 0.6·6 = 3.6 = x.
