College Algebra question ASAP help

Question

In the lab, Keiko has two solutions that contain alcohol and is mixing them with each other. She uses 100

 milliliters less of Solution A than Solution B. Solution A is 16%

 alcohol and Solution B is 19%

 alcohol. How many milliliters of Solution B does she use, if the resulting mixture has 439

 milliliters of pure alcohol?

Answer 1

A = B- 100

the alcohol content is:

16% of A + 19% of B = 100% of 439

0.16 ( B-100) + 0.19B = 438 *100% = 439*1.00 = 439

0.16 B - 16 + 0.19B = 439

0.35B - 16 = 439

0.35B = 455

35B = 45500

B = 1300

A=1200