Question

calculate the value of x

Answer 1

the sum of the angles of a triangle equal 180 degrees correct?

Answer 2

I believe:

8x + 15 = 4x + 5 + 3x + 20

Answer 3

and you know a straight angle is 180 degrees

Answer 4

so that one angle inside the triangle you don't know should be 180-(8x+15)

Answer 5

Subtract 15 to both sides:

5 + 20 - 15 = ?

Answer 6

\[(3x+20)+(4x+5)+(180-(8x+15))=180 \\ (3x+20)+(4x+5)-(8x+15)=0\]
and yep would have to agree with green's equation there

Answer 7

Yep, I got it:

http://dj1hlxw0wr920.cloudfront.net/userfiles/wyzfiles/6eb04970-3734-42f5-983e-413ca01ceb81.gif

Answer 8

Subtract 15 to both sides:

5 + 20 - 15 = ? @highjumpcollect

Answer 9

10 @iGreen.

Answer 10

Yes, so we have:

8x = 4x + 3x + 10

Now add 4x + 3x

Answer 11

7x

Answer 12

@iGreen.

Answer 13

Yes, so we have:

8x = 7x + 10

Now subtract 7x to both sides, what's 8x - 7x?

Answer 14

x

Answer 15

=10?

Answer 16

Yep, you got it.