Answer:
percentage increase: 43,75%
Explanation:
If we want to solve thai as an equation, we can write:
800 + (x/100) * 800 = 1150
we multiply: 800 + 800x/100 = 1150
we simplify: 800+ 8x = 1150
we bring the unknown to the left, and numbers to the right:
8x = 1150 - 800
8x = 350
we find x by dividing each part by 8
x= 43,75
(note that the x/100 in the first equation is the same thing as writing x%, so 800 plus a percentage of 800 is equal to 1150)