Помогите решить уравнения 115-6*х=73,540:х+85=91,18+(16-х)*8=90,(4900:у-280):60=7 плиз!!!!!!!!!!!!!!!!!!!!!!!

115-6х=73-6х=73-1156х=42х=7540:х+85=91540:х=6х=540:6х=9018+(16-х)*8=90(16-х)*8=90-18=7216-х=72:816-х=9х=16-9х=7(4900:у-280)=7*60=4204900:у=420+280=700у=4900:700=7