Q:

4(5x + 9)^2 – 33 = -21

Accepted Solution

A:
Answer:x = sqrt(3)/5 - 9/5 or x = -9/5 - sqrt(3)/5Step-by-step explanation by completing the square:Solve for x over the real numbers: 4 (5 x + 9)^2 - 33 = -21 Add 33 to both sides: 4 (5 x + 9)^2 = 12 Divide both sides by 4: (5 x + 9)^2 = 3 Take the square root of both sides: 5 x + 9 = sqrt(3) or 5 x + 9 = -sqrt(3) Subtract 9 from both sides: 5 x = sqrt(3) - 9 or 5 x + 9 = -sqrt(3) Divide both sides by 5: x = sqrt(3)/5 - 9/5 or 5 x + 9 = -sqrt(3) Subtract 9 from both sides: x = sqrt(3)/5 - 9/5 or 5 x = -9 - sqrt(3) Divide both sides by 5: Answer: Β x = sqrt(3)/5 - 9/5 or x = -9/5 - sqrt(3)/5