Answer:
x = 7
Explanation:
Since the two sides (9x - 25) of the triangle are congruent to each other, we can add them together
(9x - 25) + (9x - 25)
18x - 50
A triangle is 180 degrees when adding all three sides
So if 2 sides together equal 18x - 50 and the last side equals 104, then they should equal 180 total
18x - 50 + 104 = 180
Combine like terms
18x + 54 = 180
Subtract both sides by 54 to isolate the variable
18x + 54 - 54 = 180 - 54
18x = 126
Divide both sides by 18 to isolate the variable
18x ÷ 18 = 126 ÷ 18
x = 7
Check your work by plugging in the x value for the expression and adding all three sides to equal 180 degrees
9(7) - 25 + 9(7) - 25 + 104 = 180
Pemdas says to multiply first
63 - 25 + 63 - 25 + 104 = 180
38 + 38 + 104 = 180
76 + 104 = 180
180 = 180
The work is correct