Harsh economic realities mean trouble for college leaders. But where administrators perceive an impending crisis, investors increasingly see opportunity. In recent years, venture capitalists have poured millions into education-technology start-ups, trying to cash in on a market they see as ripe for a digital makeover. And lately, those wagers have been getting bigger. After years of avoiding the education sector, venture capitalists are scrambling to bet on the emerging market. The scramble to make bets on a tech-infused college revolution has led to so many new companies. Huge advances in computing power at colleges have created a fertile ground for companies offering technology services.