Answer:
Step-by-step explanation:
The given expression is the sum of three non-negative expressions. The square is zero or positive, the absolute value is zero or positive.
Since the sum is zero, each of the expressions should equal zero:
- 2x + 5y - 7 = 0
- 4x - 2y = 0
- 5x - 1/2y + k = 0
From the first 2 equations we get:
- 4x = 2y ⇒ y = 2x
- 2x + 5(2x) = 7
- 12x = 7
- x = 7/12
Find the value of y:
Substitute the values into third equation and find the value of k:
- 5x - 1/2y + k = 0
- 5*7/12 - 1/2(7/6) + k = 0
- 35/12 - 7/12 = - k
- 28/12 = - k
- 7/3 = - k
- k = - 7/3
