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.

the equivalent expression are always the hardest ones but you look at the gcf also

step-by-step explanation: