Question

[1^2017+(7^20÷7^19)^2-2×5^2=

Answer 1

${1}^{2017} + ( {7}^{20} \div {7}^{19} )^{2} - 2 \times {5}^{2} = \\ \\ \\ 1 + ({7}^{1} )^{2} - 2 \times 25 = \\ \\ 1 + {7}^{2} - 2 \times 25 = \\ \\ 1 + 49 - 50 = \\ \\ 50 - 50 = 0$

Answer 2

[1^2017+(7^20÷7^19)^2-2×5^2=
= 1+[7^(20-19)]^2 - 2x25 = 
= 1+7^2 - 2x25 = 
= 1+49-50 = 
= 0