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Solve (y + 2)² +5=50, where y is a real number.
Round your answer to the nearest hundredth.

1 Answer

4 votes

Answer:

y = 4.71 and y = -8.71

Explanation:

Step 1: Subtract 5 from both sides:

((y + 2)^2 + 5 = 50) - 5

(y + 2)^2 = 45

Step 2: Take the square root of both sides, subtract 2 from both sides, and round to the nearest hundredth to solve for y.

  • Remember that taking the square root will give us both a negative and positive answer on the right-hand side of the equation.
  • This is because squaring both a positive and negative number gives us. For example 2^2 = 2 * 2 = 4 but (-2)^2 = -2 * -2 = 4 also

Positive answer:

√(y + 2)^2 = √45

(y + 2 = √45) - 2

y = √45 - 2

y = 4.708203932

y = 4.71

Thus, one answer for y (rounded to the nearest hundredth) is approximately 4.71.

Negative answer:

√(y + 2)^2 = -√45

(y + 2 = -√45) - 2

y = -√45 - 2

y = -8.708203932

y ≈ - 8.71

Thus, the other answer for y (rounded to the nearest hundredth) approximately. -8.71

Optional Step 3: We can check our work by plugging in 4.71 and -8.71 for y and seeing whether we get 50. Because they're rounded, you won't get exactly 50, but the answer should be close enough for us to trust our approximations:

Plugging in 4.71 for y:

(4.71 + 2)^2 + 5 = 50

(6.71)^2 + 5 = 50

45.0241 + 5 = 50

50.0241 > 50

Our answer is close enough to 50 that we can trust our approximation.

Plugging in -8.71 for y:

(-8.71 + 2)^2 + 5 = 50

(-6.71)^2 + 5 = 50

45.0241 + 5 = 50

50.0241 > 50

Again, our answer is close enough to 50 that we can trust our approximation.

User Mike Schmidt
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