Does anyone know how to do this

The sum of two numbers is 12 and their difference is 18 what are the two numbers

Jorge wants to determine the enlarged dimensions of a digital photo to be used as wallpaper on his computer screen. the original photo was 800 pixels wide by 600 pixels high. the new photo will be 1,260 pixels wide. what will the new height be?

The function h (t) = -16t squared + 28t + 500 represents the height of a rock t seconds after it's propelled by a slingshot what does h (3.2) represent?