What is the area of a circle with an area of 400 cm squared

What is the point-slope form of theequation for the line with a slope of-2 that passes through (1, 4)? a y + 1 = -2(x + 4)b y-1=-2(x-4)c y + 4 = -2(x + 1)d y - 4 = -2(x - 1)

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?