Solve the system of equations by using a matrix
x+y=5
-2x+4y=8

Which of the following points is collinear with (-2,1) and (0,3)

Given that abcd is a rhombus, what is the value of x?

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?