15. [4] insufficient information. only given SA 16. There are 3 right triangles, 3 Pythagorean theorem equations x²+b²= 16² 12²+a² = x² a²+4² = b²
combine equations using substitution to get in terms of only x substitute b² for (a² +x²) in first equation x²+a²+4²=16² substitute a² for (x² - 12²) x²+x²-12²+4² = 16² solve for x 2x² - 144 + 16 = 256 2x² = 256 + 144 - 16 2x² = 384 x² = 384/2 x² = 192 x = 13.85
