I just need help with $5,5$a and $5b.$ Thank you

$5.$The sales manager is convinced that a $12\%$ reduction in the selling price, combined with a $$79,000$ increase in advertising, would

increase this year's unit sales by $25\%.$

a$.$ If the sales manager is right, what would be this year's net operating income if his ideas are implemented?

b$.$ If the sales manager's ideas are implemented, how much will net operating income increase or decrease over last year?