How to solve 9x+5=28
-3x-10y=-26 by elimination

So elimination
I assume that you meant to write
9x+5y=28 and not 9x+5=28
so

elimination is basically eliminating values

9x+5y=28
-3x-10y=-26
we can either cancel out the x terms or the y terms, I will cancel out the y terms

9x+5y=28
multipy both sides by 2
18x+10y=56
add to other equation

18x+10y=56
-3x-10y=-26  +
15x+0y=30
15x=30
divide both sides by 15
x=2

subsitute

9x+5y=28
9(2)+5y=28
18+5y=28
subtract 10 from both sides
5y=10
divide both sides by 5
y=2

x=2
y=2

9x + 5 = 28
      - 5   - 5
      9x = 23
       9      9
        x = 2⁵/₉

-3(2⁵/₉) - 10y = -26
    -7²/₃ - 10y = -26
  + 7²/₃             + 7²/₃
            -10y = -18¹/₃
             -10      -10
                 y = 1⁵/₆
           (x, y) = (2⁵/₉, 1⁵/₆)