Solve `a + 0.64 = 8.5` .

to solvean equation we must isolate the variable. In order to "get rid" of +0.64 we must execute the opposite operation, or subtract 0.64 from each side.

`a + 0.64 - 0.64 = 8.5 - 0.64`

`a + 0 = 7.86`

`a = 7.86`

**The solution is a = 7.86.**

This is a linear equation which you can solve in the following way.

`a+0.64=8.5`

Now you take `0.64` from left side and move it to the right side of equal sign and while you do that you must change it's sign from `+` to `-.`

`a=8.5-0.64`

`a=7.86`

**Hence your solution is 7.86.**