Strong earnings from a pair of tech giants helped the market recover some losses Friday, a positive end to Wall Street’s worst week in five months. But the gains couldn’t overcome a tough week when both the S&P 500 and the Dow saw their biggest weekly drops since last November. News that economic growth had slowed in China set off a plunge in commodity prices on Monday, leading the stock market to its worst day of the year. The market bounced back the next day, then fell again on Wednesday, its third worst day this year. This week: 10 members of the Dow and 181 companies in the S&P 500 are slated to report quarterly results.