(9r³ + 5r² + 11r) + (-2r³ + 9r - 8r²)

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Can any one me with the answers to these questions asap?

On saturday a souvenir shop had 125 customers. sixty four percent of the costumers paid with a credit card. how many costumers paid with cash?

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how