Omg me this is literally so hard like i hate this and fast

3.4a=57.8 what is the the value of a

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18

Three students each examine the system of linear equations shown. 8x + 4y = 16 8x + 2y = 8 caleb says there is exactly one solution. jeremy says there is no solution. kim says there are infinitely many solutions. which student is correct? provide mathematical reasoning to support your answer. answer in complete sentences. : d