Can someone help me with this??

Which best explains why this triangle is or is not a right triangle?

Which of the following is the correct equation for this function? a. y= (x+4)(x+2) b. y=x^2+ 3x – 2 c. y+ 2 = – 2(x+3)^2 d. y+ 2 = 2(x+3)^2

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.