Students' communication skills need to be described because they are used as communication tools in solving problems given. This study aims to find out and analyze students' mathematical communication skills and their obstacles to the topic of two-variable linear equation systems. This type of research is descriptive research. The research subjects consisted of 6 students divided in high, medium and low-ability students who were selected from 20 students, class VIII students of Riau Global IT Middle School Pekanbaru in 2018/2019. The method used is tests and interviews. The results obtained by the overall achievement were 70% of the achievement of indicators expressing mathematical ideas by speaking, writing, showing, and describing them visually, 66.7% for indicators of understanding, interpreting, and evaluating mathematical ideas presented in the form written, oral, or visual and 40% for the achievement of indicators using vocabulary, notation, and mathematical structures to represent ideas, describe relationships, and model situations. Whereas the obstacles to mathematical communication skills found are the ability of prerequisites that are not fulfilled, low reading and writing skills and low mathematical understanding of students.

The purpose of this research is to understand the meaning of revenue sharing, the method of calculating revenue sharing and the profit sharing advantage on mudharabah financing in independent Islamic banks. The results of the study show that Revenue Sharing is a profit sharing system that is calculated from the total revenue of fund management without being reduced by the cost of managing funds. So if the bank and the customer use the mudharabah scheme in carrying out working capital financing, if the business is profitable, then it must be divided based on the profit sharing portion. The advantages of mudharabah financing sharing ratio in Bank Syariah Mandiri Sengkang KCP is to be able to increase investment in third party funds on Islamic banks because if the bank uses a profit sharing calculation system based on revenue sharing where profit sharing will be distributed from total revenues before deducting with costs, the likelihood that there will be a profit sharing rate that will be received by the owner of the fund will be greater than the prevailing market interest rate.