PLZ HELP 20 POINTS Apples, a, sell for $0.75 per pound, and bananas, b, sell for $0.50 per pound. She spent $18.50 on apples and bananas. Eliza bought twice as many apples as bananas. Which system of equations can be solved to find out how many pounds that Eliza purchased of each fruit?

2a = b

0.75a + 0.50b = 18.50

2a = b

0.50a + 0.75b = 18.50

a = 2b

0.75a + 0.50b = 18.50

a = 2b

0.50a + 0.75b = 18.50