control+z = undo
Assuming I understand your question: On an IBM PC keyboard there is a key labeled Ctrl which stands for Control. For a number of functions they will say Press Ctrl plus some other key. For example, Ctrl+C (sometimes written Ctrl-C) copies just like the copy function in the Edit menu. To copy using Ctrl+C, highlight the area you want to copy, press the Ctrl key and while holding it down, press the C key on the keyboard.
Ctrl+r
It is 5x+y
(z + 15)(z + 3)
Undo is Ctrl-Z. Redo is either Ctrl-Y or in some programs Ctrl-Alt-Z.
ctrl + Z Ctrl +Z is undo for everything
Ctrl + Z is Undo and Redo (last step only), Alt + Ctrl + Z is step backward and Shift + Ctrl + Z is step forward.
It increases the magnification of the screen. CTRL plus _ does the reverse.
ctrl + a : select all
Try Ctrl + Y. There is no common universal shortcut for Redo, although you might find the option in some programs, e.g., Adobe Photoshop.
control+z = undo
Ctrl and a key are just "codes" put into software by Microsoft. Here are the only codes I know but they are very helpful in time.CTRL+C: CopyCTRL+X: CutCTRL+V: PasteCTRL+Z: UndoCTRL+B: BoldCTRL+U: UnderlineCTRL+I: Italic
Reboot
flips the screen
Ctrl-E Power off. Ctrl-R Reset the power. Ctrl-Z Suspend.
yes it does