What is d and how would i find its value

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

Which of these triangle pairs can be mapped to each other using two reflections?

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12