Find the sum of the first 20 positive integers.

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{"content":[{"content":[{"marks":[{"type":"bold"}],"text":"Step 1:","type":"text"},{"text":" The sum of the first ","type":"text"},{"attrs":{"latex":"n"},"type":"math_inline"},{"text":" positive integers is given by the formula:","type":"text"}],"type":"paragraph"},{"attrs":{"latex":"S_n = \frac{n(n+1)}{2}"},"type":"math_block"},{"content":[{"text":"Step 2:","type":"text","marks":[{"type":"bold"}]},{"text":" We want the sum for the first ","type":"text"},{"attrs":{"latex":"20"},"type":"math_inline"},{"text":" integers (","type":"text"},{"type":"math_inline","attrs":{"latex":"n = 20"}},{"type":"text","text":"). Substitute "},{"attrs":{"latex":"n = 20"},"type":"math_inline"},{"text":" into the formula:","type":"text"}],"type":"paragraph"},{"attrs":{"latex":"S_{20} = \frac{20 \times 21}{2} = 10 \times 21 = 210"},"type":"math_block"},{"type":"paragraph","content":[{"text":"So the sum is ","type":"text"},{"attrs":{"latex":"210"},"type":"math_inline"},{"text":".","type":"text"}]}],"type":"doc"}

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