Solve 6x+2=2x-2 these sort of equations i cannot understand

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

Tod does not have any cookies. david gives jeff 8 cookies. then he splits half of the cookies he has left with tod. david let’s c represent the number of cookies that he starts with. he finds the number of cookies that tod has is 1/2 the difference of c and 8. write an expression to represent the number of cookies that tod has.

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?