Question 118303
First let's add them



{{{(2a^2+3ab-5b^2)+(b^2-ab)}}}   Start with the given expression


{{{(2a^2)+(3ab-ab)+(-5b^2+b^2)}}} Group like terms


{{{2a^2+2ab-4b^2}}} Combine like terms


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Now let's subtract them





{{{(2a^2+3ab-5b^2)-(b^2-ab)}}}   Start with the given expression



{{{2a^2+3ab-5b^2-b^2+ab}}}   Distribute the negative


{{{(2a^2)+(3ab+ab)+(-5b^2-b^2)}}} Group like terms


{{{2a^2+4ab-6b^2}}} Combine like terms