Barb signed up for an art club. She had to pay $50 to sign up for the club and $8 each week that she attended it. If she spent a total of $90, how many
weeks did she go to the club?

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?

Marcus needs to bike at least 80 miles this week for his training. if he has already biked 25 miles this week, then how many miles should he bike on each of the 5 remaining days this week ?

The equation for two lines in the coordinate plane are 2dx+y=4 and -6x+y=3, where d represents an unknown value. what value(s) of d would make these lines parallel?