64.6k views
4 votes
PLEASE HELP!!!!! 

What is ​ BC ​?



Enter your answer in the box.
units

PLEASE HELP!!!!!  What is ​ BC ​? Enter your answer in the box. units-example-1
User Farwa
by
6.7k points

2 Answers

3 votes

8x - 4 = 5x + 11 \\ 3x = 15 \\ x = 5

Substitute that into 4x - 2,

4(5) - 2 \\ = 20 - 2 \\ = 18

Answer : BC = 18

Hope this helps. - M
User Kusanagi
by
6.3k points
2 votes

We are given an isosceles triangle ABC. Where AB = AC.

AB = 8x -4

AC = 5x +11.

BC = 4x -2

We need to find the length of BC.

We have AB = AC.

Therefore,

8x -4 = 5x +11.

Let us solve it for x now.

Adding 4 on both sides, we get

8x -4+4 = 5x +11+4.

8x = 5x +15.

Subtracting 5x from both sides, we get

8x -5x = 5x-5x +15

3x = 15.

Dividing both sides by 3, we get

3x/3 = 15/3

x = 5.

Plugging x=5 in BC = 4x -2 .

BC = 4(5) -2 = 20-2 =18.

Therefore, length of BC is 18 units.

User Jett Chen
by
7.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.