Does the equation represent a direct variation. if so, find the constant of variation.
5x= -3y
a. no
b: yes k= -5/3
c yes k= 5/3
d yes k= -3/5

6(2x+y)+2(x+4y) how can i solve this

Ateacher has $80 to buy workbooks. each work book cost $3. if she buys as many workbooks as possible, how much money does she have leftover? a) $2 b) $4 c) $6 d) $8

Maria donates a fixed amount, a, to a charity each month. if she donates $300 in 12 months, what is the equation for a? a. a + 300 = 12 b. a × 300 = 12 c. a × 12 = 300 d. a + 12 = 300 e. a + 32 = 100