SAN FRANCISCO — SoftBank formally started off its approach for buying a major stake in Uber with an offer to acquire some shares at a valuation of $forty eight billion, significantly under the almost $70 billion valuation that the trip-hai…

SAN FRANCISCO — SoftBank formally started its method for buying an important stake in Uber with a suggestion to invest in some shares in a valuation of $forty eight billion, far beneath the almost $70 billion valuation that the ride-hailin…