Answer:
It cost 30$
Step-by-step explanation:
Since 50% is 1/2 we put 80/2
so we have 40
25% is 1/4 we put 40/4=10 40-10=30
so the answer is 30
x=10
x-1 = 9
add 1 on both side
x-1+1=9+1