Tavon has a gift card that loses $4 for each 30-day period it is not used. he has another giftcard for $85 that loses $3.50 for each 30-day period it is not used. A) Write and solve an equation for the number of 30-day periods until the value of the gift cards will be equal

B) what will the value of each card be when they have equal value

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

answer: 0,6

step-by-step explanation:

this would make it the y intercept.