This is good, the mistakes you make are at quite an advanced level and are often the type of mistake an English speaking pupil would also make commenting on these graphs. Keep up the good work

IELTS Task 1. Could you please correct my notes? Thank you in advance

The first bar graphs charts illustrate the proportions of students who study, split by in different age groups, according to two main reasons, and the second shows the amount of employer’s support they students can receive at work.
As the first bar graph demonstrates, in all age group, except for student aged over 49, more students study because of their career and not than out because of their Interest. For more illustrationMore specifically, as the students get older their career reasons for study the proportion who study for their career declines gently <"steadily" is a better adverb>, while their interest for studying grows  goes up at a constantly rate. Around 80% of students under 26 years olds prefer to study for their career, as opposed to merely 10%, who merely studying for their interests. The Percentage of students between 26 to 39 years of age groups decrease by 10%-20% in career reasons, while the interest reasons for these two age groups increase moderately by approximately 10%.

The Percentage of students in the 30-39 age group who study for career reasons is between 10 and 20% lower than those in the 26-29 age group, while those who study out of interest increases by approximately 10% between these two groups.
However, about 40% of students who are in their 40s study for either their career and also 40% for interest reasons. In contrast, around 70% and slightly fewer than 20% of those who are over 49 are studying for interest and career reasons respectively.
Furthermore, employees under 26 years old receive the highest support from their employer at around 60%, whereas 30 to 39 year olds receive only 30% of their employment support <unclear from the graph but I think it is> only 30% of students between 30 and 39 recieve support from their employers. The employer supports for older employees (who are those over 40) increases constantly to nearly 40%.

<PS. an increase from 30% to 40% is not a 10% increase but a "10 percentage point increase"; a 10% increase would be 33%. However that is a mathematics mistake that many many English speakers make including Journalists!>