Chapter 10 - Geometry - 10.1 Points, Lines, Planes, and Angles - Exercise Set 10.1 - Page 617: 43

$x=5^\circ$ $2\times 5^\circ+50^\circ=60^\circ$ $4\times5^\circ+10^\circ=30^\circ$

The two given angles form a right angle, which means that their sum is $90^\circ$. $2x+50^\circ+4x+10^\circ=90^\circ$ $6x+60^\circ=90^\circ$ $6x=30^\circ$ $x=5^\circ$ The two angles are: $2\times 5^\circ+50^\circ=60^\circ$ $4\times5^\circ+10^\circ=30^\circ$