Please explain how to combine them into one standard form equation.

9514 1404 393

  e.  7x -y = -5

Step-by-step explanation:

Rearranging the first equation to general form, we have ...

  7x -2 = 0 . . . . subtract 5 from both sides

Rearranging the second equation to general form, we have ...

  y -7 = 0 . . . . . subtract 6 from both sides

Now, we can equate these expressions for 0:

  7x -2 = y -7

Subtracting y gives ...

  7x -y -2 = -7

and adding 2 gives the standard form equation ...

  7x -y = -5 . . . . matches choice E

Comment on the question

Mathematically, there is no good reason to do this. It seems to be simply an exercise in manipulating equations.

Here, we subtracted the y-equation from the x-equation to get the final result. There are many other ways an expression for "0" can be used to combine these equations.

-22

times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3