Which is the best first step when solving the following system of equations? y= 7x+3 y=9x

Need on this one asap im almost done with this subject

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

One hectometer is a) 1/1000 of a meter. b) 1/100 of a meter. c) 10 meters. d) 100 meters. e) 1000 meters.