What is the missing step in this proof? (i'll add screenshots when i figure out how)

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.

The area of each triangle is 7 square units. the surface area of the triangular prism is

Give the domain and range. a. domain: {0, 2, 4}, range: {2, 6, 10} b. domain: {0}, range: {2} c. domain: {2, 6, 10}, range: {0, 2, 4} d. domain: {2}, range: {0}