Sequences and Series

Let l1,l2,...,l100 be consecutive terms of an arithmetic progression with common difference d1, and let w1,w2,...,w100 be consecutive terms of another arithmetic progression with common difference d2, where d1d2=10. For each i=1,2,...,100, let Ri be a rectangle with length li, width wi and area Ai. If A51−A50=1000, then the value of A100−A90 is_____