Kara has 21 collectible buttons to sell. she sells the small buttons for $3 and the large buttons for $4, and earns a total of $68. if the small buttons are represented by x and the large buttons are represented by y which of the following systems of equations can be used to calculate the number of large and small buttons sold. answersx+y=21,3x+4y=68x+y=68, 3x+4y=21x+y=21, 4x+3y=68x+y=68, 4x+3y=21

We know that there are 21 buttons total. x is the number of small buttons and y is the number of large buttons. 

Therefore, our first equation should be x+y = 21.

We know the small buttons sell for 3 dollars, meaning 3x represents how much is made from the small buttons. The larger buttons sell for 4 dollars, meaning 4y is how much is made from the large buttons. 

We also know that the total of the buttons sold is 68 dollars. Therefore 3x + 4y = 68 is our second equation.

From this information, the answer is the first set.