MathematicsMedium244×since 2002Q4513Let A=[2a013105b]A=\left[\begin{array}{lll}2 & a & 0 \\ 1 & 3 & 1 \\ 0 & 5 & b\end{array}\right]A=210a3501b. If A3=4A2−A−21IA^3=4 A^2-A-21 IA3=4A2−A−21I, where III is the identity matrix of order 3×33 \times 33×3, then 2a+3b2 a+3 b2a+3b is equal toA−10-10−10B−12-12−12C−13-13−13D−9-9−9Check answerSkip