Answer:
20%-X=a
Step-by-step explanation:
So if there is a toy that cost $50 and it was 20% off it would then cost $40
Answer:
y = 
Step-by-step explanation:
y = log 5 2x
inverse ------> y=x
x = log 5 2y

y = 
(12+8)\ 5 + 15=19... this solution works because 12+8=20.. 20/5=4 and then 4+15=19