One possible solution:
13,4 - у = 4,3 - 20,013,4 - у = -15,7у = 13,4 + 15,7у = 29,15
Now we substitute у back into the second equation:
78,05 + 6,7(29,15) = 78,05 + 195,8078,05 + 195,805 = 273,855
Therefore, the solution is у = 29,15 and the final answer is 273,855.
One possible solution:
13,4 - у = 4,3 - 20,0
13,4 - у = -15,7
у = 13,4 + 15,7
у = 29,15
Now we substitute у back into the second equation:
78,05 + 6,7(29,15) = 78,05 + 195,80
78,05 + 195,805 = 273,855
Therefore, the solution is у = 29,15 and the final answer is 273,855.