please i need help! this is timed and i need to find the height of the pyramid. any tips appreciated:)

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36

Which line is parallel to the line that passes through the points (2, –5) and (–4, 1) a. y=-x+5 b. y=-2/3x+3 c. y=2/3x-2 d. y=x+5