The coordinates of the vertices of triangle abc are a(-1,3), b(1,2) and c(-3,-1).

determine the slope of each side of the triangle and use that information to determine if the triangle is a right triangle or not.

Two years ago a man was six times as old as his daughter.m- 2 = 6(d-2)m - 2 = 6d - 12m = 6d - 12 + 2m = 6d - 10: in 18 years he will be twice as old as his daughter.m + 18 = 2(d+18)m + 18 = 2d + 36m = 2d + 36 - 18m = d + 18from the 1st equation, replace m with (6d-10)6d - 10 = 2d + 186d - 2d = 18 + 104d = 28d = 28/4d = 7 yrs is the daughter's agefind dad's agem = 6(7) - 10m = 42 - 10m = 32 yrs is dad's age: : check solutions in the statement: "in 18 years he will be twice as old as his daughter."32 + 18 = 2(7 + 18)50 = 2(25) 

$6,229 to the nearest dollar