Answer:
a = 9 + b - c → D
Step-by-step explanation:
To cancel the square root of one side of an equation square the two sides
Examples:
If [tex]\sqrt{x}[/tex] = 5, to find x square the two sides to cancel the square root
([tex]\sqrt{x}[/tex] )² = (5)², then x = 25
If [tex]\sqrt{a+b}[/tex] = 7, to find a + b square the two sides to cancel the square root
([tex]\sqrt{a+b}[/tex] )² = (7)², then a + b = 49
Now let us solve the question
To solve it for a square the two sides then keep a on the left side and move b, c to the other side
∵ [tex]\sqrt{a-b+c}[/tex] = 3
→ Square the two sides to cancel the square root
∴ ([tex]\sqrt{a-b+c}[/tex])² = (3)²
∴ a - b + c = 9
→ Add b to both sides to move b from the left side to the right side
∴ a - b + b + c = 9 + b
∴ a + c = 9 + b
→ Subtract c from both sides to move c from the left side to the right side
∴ a + c - c = 9 + b - c
∴ a = 9 + b - c
