Question

SOS

Answer 1

\(=\left\{\left[45.\left(79+21\right)\right]:90-5^{12}:5^{10}\right\}:5^0-2^3\)
\(=\left[\left(45.100\right):90-5^2\right]:1-8\)
\(=\left(4500:90-25\right)-8\)
\(=\left(50-25\right)-8=25-8=17\)

Answer 2

[(45×79+45×21)÷90-5^12÷5^10]÷5^0-2^3

= [3555+945)÷90-5^2)÷1-8

= (4500÷90-25)-8

= (50-20)-8

= 25-8

= 17