Could anyone help me with this ASAP ?

Determine whether the graphs of y=8x+5 and -y=8x-5 are parallel, perpendicular, coincident, or none of these. a. coincident b. parallel c. perpendicular d. none of these

Ineed i been stuck on this question since yesterday

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.