Help plz
find the size of unknown angle in the flowing figures

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

What expression is equivalent to log3(x+4)

Complete the solution of the equation. find the value of y when x equals to 1 9x-5y=29