algebra
posted by bianca on .
The final grade for a particular course is calculated by dividing total points earned by total points available. There are 120 points available in the first half of the course, and 140 points in the second half of the course. If a student earns 81% in the first half ofthe cours, how many pnts must the student earn in the second half in order to earn an 80% B final grade?
To put this in algebriac equation would be
140+120=260*.80=208
120*97
208*97=111
120X=81%
X=111
I know this is not a correct algebraic expression could you explain how to write this in correct algebraic expression. Thanks for your help

.81(120) + x(140) = .80(260)
81(120) + 100x(140) = 80(260)
1400x = 11080
x = 11080/1400 = .7914
the student must earn 79% of 140 or 110.8 points in the second semester.