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6 votes
6 votes
Solve for X please show work and or formula

Solve for X please show work and or formula-example-1
User Mreithub
by
2.6k points

2 Answers

15 votes
15 votes

Answer:

x = -9

Explanation:

Notes to remember:

A triangle's angles will always add up to 180°

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As the image shows, we have two labeled angles. A 51° angle and a 65° angle.

Here's how you want to set up your equation:

180° = 51 + 65 + x + 73

(Rearrange)

180° = 51 + 65 + 73 + x

Add 51, 65, and 73

180° = 189 + x

Subtract 189 from both sides, to isolate x.

-9° = x

ALWAYS PLUG IN (the number that comes from the variable) TO CHECK YOUR WORK!

180° = 51 + 65 - 9 + 73

I hope this helped!

Sincerely,

Your friendly neighborhood

Middle School Math Teacher

User Major
by
2.9k points
17 votes
17 votes

The sum of angles in a triangle is always equal to 180 degrees

Add:

65 + 51 + x + 73 = 180

x + 189 = 180

x = -9 That is fine that x is "-9" because this would just mean that the angle "x+73" is just bigger than it is supposed to be.

Proof:

65 + 51 - 9 + 73 = 180

Therefore, x = -9

User Nghia Luong
by
3.0k points