Answer:
2.5
Step-by-step explanation:
a=1 and b=5 so it would be 1 times 5 minus 0.5 time 5. to get this you must used PEMDAS and multiplication goes before subtraction. 1 times 5 is 5 and 0.5 times 5 is 2.5 so now you can subtract one from another which would give you your answer.