Can someone help me with this?

Find the solution of system of equation y= x-4 y=4x+2

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie

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