SOMEONE HELP ME WITH THIS PLS

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Step-by-step explanation:

You add the "columns."  The equations are arranged so that like terms are stacked vertically.  3x and 7x are like terms; when you add them, you get 10x.

-y and y are like terms; when you add them, you get 0 (that doesn't appear in the sum).

-5 and 15 are like terms; add them to get 10.

The sum of the two equations is the equation 10x = 10.

b. 10=9.1+0.2x

step-by-step explanation:

that's it