a baker baked some muffins and brownies for sale.45% of the pastries were muffins. After selling a equal amount of muffins and brownies, 40% of the pastries were left. He had 30 more brownies than muffins. How much muffins did he sell?

He sold 15 muffins. There were 135 muffins and 165 brownies in the start.

To solve this integral, what you can do is split it up as follows: (1) ∫40(x2−4)dx=∫40(x2)dx−∫40(4)dx. to integrate  4  as an  indefinite integral, a good rule of thumb is  by  an equation below  for  polynomials; . (2) ∫xa=xa+1a+1+c , where a is any number. c denotes some constant that is crucial when doing 

If it’s 15 minutes it would be 159