How do i evaluate 30-xy+2 if x=-2 and y=-6

Eric drew a scale drawing of a country park. the scale he used was 1 inch = 2.5 yards. the picnic area is 80 yards wide in real life. how wide is the picnic area in the drawing ?

Sarah used her calculator to find sin 125 degrees. she wrote down sin sin125 degrees.57. how could sarah recognize that her answer is incorrect?

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.