Help me please I don’t know thank you

Which of the following would represent the sum of 3 consecutive integers if x is the first integer?

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?

Urgent need asap △abc is similar to △xyz. also, side ab measures 6 cm, side bc measures 18 cm, and side xy measures 12 cm. what is the measure of side yz ? enter your answer in the box.