Which equation is written in standard form ? a. y-3 = -5(x+2)
b. y= 1/2x + 2
c. 3x + 2 = y
d. -7x + 2y = 9

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

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).

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees