Use photomath ! It's an app that gives you the answer with the explanation and it shows you how it got to the answer !
Answer:
-5
Step-by-step explanation:
8x + 7y = 39
4x - 14y = -68
(multiply each term in second equation by -2)
8x + 7y = 39
-8x + 28y = 136
(add both equations)
35y = 175
(divide both sides by 35)
y = 5
(substitute value of y in one of the equations)
8x + 7(5) = 39
8x + 35 = 39
8x = 4
x = 1/2
(x, y) = (1/2, 5)
$260
I don’t know what model/formula you are supposed to be using.
But what I did first was calculated what 30% of 2700$ is.
2700 x .3 = 810
So it depreciates $810 per year.
$810 x. 3 years = 2430
2700 - 2430 = 260
In three years, the laptop will be worth $260
Do you mean this?
x= sqrt{2(w-y)}