Question

the diagram shows a triangle.
what is the value of u?
u = \square^\circ

Explanation:

Step1: Sum angles to 180°

$(2u+5) + (2u+11) + (u-1) = 180$

Step2: Simplify left side

$2u+5+2u+11+u-1 = 5u+15$

Step3: Solve for u

$5u+15=180$
$5u=180-15$
$5u=165$
$u=\frac{165}{5}$

Answer:

$33$