What is the value of x + y + z when 6x + 5y - 2z = -4 and 4x + 5y + 12z = 54? i'm really stuck on this problem. can someone ?

Which inequality has a dashed boundary line when graphed ?

How to find the exponential function y=ca^x, with points (1,2) and (2,1)

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth