Estimate the solution of a^2=21 to the nearest tenth

This needs to be done quick you are studying different function tools and begin working with this function y=-160-9(x) use the equation to answer the question y=-160-9(x) what is the y value when x equals -13? y=-160-9(x)

Which region represents the solution to the given system of inequalities? |-0.5x+y23 | 1.5x+ys-1 5 4 -3 -2 -1 1 2 3 4

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²