A= $\frac{4}{4.7}$ + $\frac{4}{7.11}$ + $\frac{4}{11.15}$ + ... + $\frac{4}{1023.1027}$
A= $\frac{1}{4}$ - $\frac{1}{7}$ + $\frac{1}{7}$ - $\frac{1}{11}$ + $\frac{1}{11}$ - $\frac{1}{15}$ + ... + $\frac{1}{1023}$ - $\frac{1}{1027}$
A= $\frac{1}{4}$ - $\frac{1}{1027}$
A= $\frac{1023}{4108}$
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