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Point b is between A and C. if AB =2x, BC =3x+1, and AC=21, find the length of BC

User Jehong Ahn
by
8.1k points

2 Answers

6 votes

Answer:

+ BC = AC

x + 2x+1 = 22

3x +1 = 22

3x = 21

x = 7

AB = 7

BC = 2*7+1 = 14 + 1 = 15

15 - 2

13

User Domen Vrankar
by
7.2k points
5 votes

Explanation:

We are here given that a point B is between A and C . Also ,

  • Value of AB = 2x
  • Value of BC = 3x + 1
  • Value of AC = 21 .

And we would like to calculate the length of BC . For figure refer to the attachment. From figure we can see that ,


\rm:\implies AC = AB + BC

Substitute the respective values,


\rm:\implies 21 = 2x + 3x + 1

Add like terms ,


\rm:\implies 21 = 5x +1

Subtract 1 on both sides,


\rm:\implies 21-1 = 5x

Simplify,


\rm:\implies 20=5x

Divide both sides by 5,


\rm:\implies \blue{ x = 4}

Now consider ,


\rm:\implies BC = 3x+1

Plug in the value of x found above ,


\rm:\implies BC= 3(4)+1

Simplify,


\rm:\implies BC = 12+1

Add,


\rm:\implies \underline{\boxed{\blue{\rm{ \quad BC \quad =\quad 13\quad }}}}

And we are done !

Point b is between A and C. if AB =2x, BC =3x+1, and AC=21, find the length of BC-example-1
User Jfsantos
by
7.5k points

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