Given vectors ā=(-1,-2), b =(-2,-3), c = 2,-1,2 = -3,2) Use the dot product and scalar multiplication to determine whether the vectors b and d are orthogonal, parallel or
neither

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

X+y=-4 x-y=2 use elimination with adding and subtraction

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.