Solving Systems of Equations
Solving
Systems of
Equations- Copy the calculated solutions to the system of equations and place them
into the cells that will check these answers against the original equation
In cell L23, enter the following formula:
=$q$20
Copy and use Paste Special again to copy into cell L25.
In cell O23, enter the following formula:
=$q$21
Copy and Paste Special into cell O25. - Enter a checking formula.
In order to make sure the worksheet (and student) has calculated the an-
swers correctly, you do not want to simply copy the values from Q9 and Q11
directly into Q23 and Q25. That would give the appearance of a correct an-
swer even if it was wrong. You need a formula that uses the worksheet an-
swers and substitutes them back into the original equations. In cell Q23,
enter the following formula:
=k23l23+n23o23
Then use Ctrl+C and Paste Special to copy the formula into Q25. - To “student-proof” this worksheet, you are going to use Protection to lock
the cells with formulas, while allowing user input where needed.
There are only nine cells that need to be unlocked. Click on cell K9, press
and hold the Ctrl key, and then click on N9, Q9, K11, N11, Q11, I13, I15,
and I20. Press Ctrl+1 to open the Format Cells dialog box, and click the
Protection tab. Click the box next to the word Locked. Click OK to exit.
Figure 266
Using Format Cells to unlock
certain cells