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Provide a small explanation if possible!!

Solve 2x+y=3 x+y=5 in substitution method

If square root x = -7, then x= -49 true or false

50 people men and women were asked if they watched at least one sport on tv. 20 of the people surveyed are women, but only 9 of them watch at least one sport on tv. 16 of the men watch at least one sport on tv. make a a two-way table and a relative frequency table to represent the data.