Câu a.
\(2^4-50:25+13.7=16-2+91=105\)
Câu b.
\(4.\left\{3^2.\left[\left(5^2+2^3\right):11^1\right]-26\right\}+2002\)
\(=4.\left\{9.\left[\left(25+8\right):11\right]-26\right\}+2002\)
\(=4.\left[9.\left(33:11\right)-26\right]+2002\)
\(=4.\left(9.3-26\right)+2002=4.\left(27-26\right)+2002=4.1+2002=2006\)