3x+6y=18 what is the y value when x=2

Mrs. foyle told yolanda that her test had 38 problems worth a total of 100 points. each test problem is worth either 5 points or 2 points. yolanda wanted to determine how many 2-point and how many 5-point questions are on the test. in the space below, determine how many questions of each point-value are on the test. show your work or provide an explanation to support your answer. need this asap