What is the missing value for x-5y=-15

Atrucker had a load of grain containing 2 tons. she unloaded 1 ton and 1,200 pounds at the warehouse. how much grain does she still have left on the truck?

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

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?