I did this myself, but I kept getting negative numbers can someone else try and do this and see what you get ​

6

Step-by-step explanation:

67

Step-by-step explanation:

4x = 2x + 12

4x - 2x = 2x - 2x + 12

2x = 12

2x ÷ 2 = 12 ÷ 2

X = 6

Plug into HI

9 × 6 + 13 = 67

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: