Solve each system of linear equations by substitutions.
1. 3x-2y=9 y=2x-7
2. y=x-4 2x+y=5
3. x+4y=6 y=-x+3

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.

Describe the symmetry of the figure. identify lines of symmetry, if any. find the angle and the order of any rotational symmetry.