Explanation:
Complementary angles mean that the sum of the angles equals 90 degrees.
This means that
A+B=90
(2x-13)+(4x-5)=90
expand and simplify
2x+4x-13-5=90
6x = 90+18 = 108
x = 108/6=18 degrees.
=>
B=4x-5=4*18-5=72-5=67 degrees
check:
A=2x-13=2*18-13=36-13=23 degrees
A+B=23+67=90 degrees => A and B are complementary