How many elements are there in a 7x2 matrix?

Both the red and blue line segments stretch from the center of the circle to a point on the circle. the length of the blue segment is 5. how long is the red line segment?

What is the slope-intercept form of a line that passes through points (2, 11) and (4, 17)? y=-3x-5 o y=3x-5 y=-3x+5 0y=3x+5

Find the value of x. also give me an explanation so i can complete it to other questions as well, : )