Determinati numerelex y z stiind ca x/3=y/5=z/9 Aflati:
a) xy+yz+zx=1392
b) 7x^2 + 9y^2+ 2z^2

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers