Solve the following system of equations. enter the y-coordinate of the solution. round your answer to the nearest tenth
5x+2y=7
-2x+6y=9

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?

Angles 1 and 2 are complimentary angles. angle 1 = 52 degrees. what is the measure of angle 2?

The coverage of a base station of a telecommunication company forms a disk with a radius of (kilometers). let be the distance of a cellphone from a base station. assume that the location of cellphones in use are randomly uniformly distributed within the disk. calculate the mean and variance for the random variable.