12 squared plus 8 squared equals what number squared?

Asystem of equation is shown below 6x - 2y equals 3 . and 5x + 3y equals 4. would you solve by substitution or elimination? and why

Select the quadratic that has root x = 8 and x = -5

The suare root of 9x plus 7 plus the square rot of 2x equall to 7