Im 148 lbs and 5'1, how long will it take me to lose about 40-50 lbs with hip hop abs and eating less?

No way to predict: That varies a great deal from one person to another. It is much more difficult for some people to lose weight than it is for others. Losing 40-50 lbs is a very difficult thing to do. It requires a great deal of dedication and consistency. It would be more realistic to set a goal of losing 10 lbs and see how long that takes. It will probably take longer with each 10 lbs that you lose.

Weight loss: Everyone is different. Shoot for a consistent 3-4 pound weight loss per week with diet & exercise.

1year: Realistically, about a pound a week weight loss should be a goal to aim for, so about a year to lose 40-50 pounds. If your starting weight is extremely high, say with a BMI over 45, you can manage a faster weight loss of 2-3 pounds per week, so 100-150# in a year. Anything faster not healthy and may deprive you of essential nutrients and vitamins. Make a lifestyle change, not just x# to lose!

Eat Better.: "Eating less" is not necessarily the answer. A more easier to follow approach would be "eating better". You are probably on a carbohydrate heavy diet. You must assess you dietary input before you can determine just what has to change. A better diet along with slowly increasing exercise sessions will better assure you of success.