ANSWER
![x = 25 \degree](https://img.qammunity.org/2019/formulas/mathematics/middle-school/bk5boww77k54bozg9rn11l8bfoldzn6ysi.png)
EXPLANATION
The sum of the interior angles of a triangle is
![180 \degree.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xtn32oudb90qpokloburlp069rpf00e8xs.png)
In a right angle triangle, one of the angles is already
![90 \degree.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nn39xhzh0x77ozunw854lnjxct9wgx8zke.png)
Therefore the remaining two acute angle will add up to
![90 \degree.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nn39xhzh0x77ozunw854lnjxct9wgx8zke.png)
This implies that,
![(2x - 11) + (x + 26) = 90 \degree](https://img.qammunity.org/2019/formulas/mathematics/middle-school/dyck9tpq23o3etwv0txm1uk62xqr1yeqdz.png)
We group like terms to get,
![2x + x + 26 - 11 = 90](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4heewfbsbvx5mdwpo6png3tb3ekok7xoho.png)
This gives us,
![3x + 15 = 90](https://img.qammunity.org/2019/formulas/mathematics/middle-school/3w9rj64zsze3lydgpd8wltse4e2pbwnpu9.png)
This gives,
![3x = 90 - 15](https://img.qammunity.org/2019/formulas/mathematics/middle-school/vxhjeyo5u5z61y8h5q9auzr9b24jyg2zt8.png)
![3x = 75](https://img.qammunity.org/2019/formulas/mathematics/middle-school/npa0ojsdyyoke0end2uc6k7kxhq06ku492.png)
We divide both sides of the equation by 3 to obtain,
![x = 25 \degree](https://img.qammunity.org/2019/formulas/mathematics/middle-school/bk5boww77k54bozg9rn11l8bfoldzn6ysi.png)