Mike bought 5 new baseball trading cards to add to his collection . the next day hos dog ate half of his collection. there are now only 40 left. how many cards did mike start with?

i think the answer would be 75

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x