For this case we propose a system of equations:
x: Let the variable representing the quantity of Granny Smith apples
y: Let the variable representing the number of Gala apples
According to the statement we have:
From the first equation we have to:
replacing in the second equation:
So, Carl bought 7 Gala apples
On the other hand:
So, Carl bought 12 Granny Smith apples
Answer:
Carl bought 7 Gala apples and 12 Granny Smith apples
Answer: x" = 5.69
Step-by-step explanation:
The graphic solution is attached.
Verifying the solution:
Existence condition: x > 0
2x - 4 = √x + 5
√x =2x - 4 - 5
√x =2x - 9 (²)
x = (2x - 9)²
x = 4x² - 36x + 81
4x² - 36x - x + 81 = 0
4x² - 37x + 81 = 0
Δ = -37² - 4.4.81 = 1369 - 1296 = 73
x = 37 ±√73/8
x' = 3.55
x" = 5.69
checking:
2*3.55 - 4 = 3.1
√3.55 + 5 = 6.88 Its not the same ∴ 3.55 is not a solution
2*5.69 - 4 = 7.39
√5.69 + 5 = 7.39 ∴ it's the only solution
