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8 votes
If DF=9x-39, find EF

User Squis
by
6.8k points

1 Answer

4 votes

Answer:


EF = 58

Explanation:

Given


DF = 9x - 39


DE = 47


EF = 3x + 10

See attachment

Required

Find
EF

Because E is a point between D and F, then:


DF = DE + EF

Substitute values for DF, DE and EF


9x - 39 = 47 +3x + 10

Collect Like Terms


9x -3x = 47 +39 + 10


6x = 96

Make x the subject


x = (96)/(6)


x = 16

Recall that:


EF = 3x + 10

Substitute 16 for x


EF = 3 *16 + 10


EF = 48 + 10


EF = 58

If DF=9x-39, find EF-example-1
User Protocole
by
7.2k points
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