Answer:
x = 21.7°
Explanation:
We know that the sum of the three angles in triangle add up to a total of 180°.
So adding the given expressions of angles and putting them equal to 180 to find the value of x:
![(3x-5) + (2x+20) +(4x-30)= 180](https://img.qammunity.org/2019/formulas/mathematics/college/zzqmiy2xvqlo69rpe4wil2nprgto1yepql.png)
![4x+3x+2x+20-30-5=180](https://img.qammunity.org/2019/formulas/mathematics/college/q3p4nt9odpcq6rmgl3m21icxmfnp7xd2al.png)
![9x=180+30-20+5](https://img.qammunity.org/2019/formulas/mathematics/college/p1u8z523s1v8d7cehig0ft2xjppdjcptyr.png)
![9x=195](https://img.qammunity.org/2019/formulas/mathematics/college/bjmb5ar5akt2sd4pu4sxlu4x81jpcg0dk1.png)
![x=(195)/(9)](https://img.qammunity.org/2019/formulas/mathematics/college/q6nkbg2qu4i1pvsxetbbos779hm9vttr5b.png)
![x=21.7](https://img.qammunity.org/2019/formulas/mathematics/college/8lhyxxwn7cz9ngaqs5g6cg7aw2e13mm4yo.png)
Therefore, the value of x in a triangle with angles 3x-5, 2x+20, 4x-30 is equal to 21.7°.