$$\text { Find the values of } \sum _ { j = 1 } ^ { 100 } 2 \text { and } \sum _ { j = 1 } ^ { 100 } ( - 1 ) ^ { j } \text {. }$$

Essay

$$\text { Find the values of } \sum _ { j = 1 } ^ { 100 } 2 \text { and } \sum _ { j = 1 } ^ { 100 } ( - 1 ) ^ { j } \text {. }$$