Annika sells 6 inch pies for $5.00 and 8 inch pies for $9.00 each. last week she sold twice as many 6 inch pies as she did 8 inch pies. she made $133.00 from her sales. annika defined x as the number of 6 inch pies she sold and y as the number of 8 inch pies she sold. she wrote the system below. which statements about the system are true? check all that apply.