Answer:
9
Step-by-step explanation:
To calculate the value of x we must first understand the total value of all angles in a triangle.
Sum of all angles in a triangle = 180 degrees
That said, we need to write an equation for the total number of degrees in the triangle and solve for x
This will be as follows:
(13x+2)+(5x-7)+(3x-4)=180
The we combine the like terms. This will be as follows:
(13x+5x+3x)+(2-7-4)=180
Simplify further to get
21x-9=180
Simplify further by collecting all like terms on one side of the equal. This will entail the addition of 9 on each side of the equal sign as follows:
21x-9+9=180+9
you will find 21x=189
Simplify further by dividing both sides of the equal sign by 21 to solve for x
21x/21=189/21
Therefore x=9
