Adding integers with different signs is just like adding or subtracting. First you just have to add all negative integers and also add all positive. After that positive intergers will be deducted by the sum of negative integers
A=adult
c=children
total lumber=30
total number=adults+children
a+c=30
total cost=50
total cost=acost+ccost
acost=a times cost per adult=a times 3=3a
ccost=c times cost per child=c tiems 1=1c=c
total cost=3a+c
50=3a+c
equiaotn are
a+c=30
3a+c=50
multiplyu first by -1 and add
3a-a+c-c=50-30
2a=20
a=10
sub
10+c=30
c=20
answer is A
X = 28% * 80
x = 28/100 * 80
x = 28/10 * 8
x = 2.8 * 8
x = 22.4
28% of 80 is 22.4.
Your final name is a. 22.4