Question

Answer 1

\(a,11-12+13-14+15-16+17-18+19-2\\ =\left(-1\right)+\left(-1\right)+\left(-1\right)+\left(-1\right)+17\\ =-4+17\\ =13\\ b,2^2.3^1-1^{2012}+2021^0:2\\ =4.3-1+1:2\\ =12-1+\dfrac{1}{2}\\ =11+\dfrac{1}{2}\\ =\dfrac{22+1}{2}\\ =\dfrac{23}{2}\\ c,\left\{47-\left[736:\left(5-3\right)^4\right]\right\}.2021\\ =\left\{47-\left[736:2^4\right]\right\}.2021\\ =\left[47-46\right].2021\\ =\left(-1\right).2021\\ =-2021\)