How do i put y= 75x +1,200 in standard form into ax+ by=c

Mp model with mathematics explain how the number of text messages dario sent and the cost form an arithmetic sequence.then write an expression to find dario's text messaging bill if he sends n text messages over 250.

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

Me n o w. i need t h i s. 10 points