18+(16-х)*8=90помогите и второе (4900:у-280):60=7

1) 18+(16-х)*8=9018+128-8x=90146-8x=90-8x=90-146-8x=-56x=72) (4900:у-280):60=7 (4900/y-280)*1/60=74900-280y/60y=74900-280y/60y=7, y 020(245-14y)/60y=7245-14y/3y=7245-14y=21y-14-21y=-245-35y=-245y=7, y0y=7