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3 years ago

Solve for x. 8x^2 - 5 = 11

Mathematics

2 answers:

Mrrafil [7]3 years ago

7 0

X = 1

8x^2 turns to 16x
Add five on each side of the equation, totaling 16.
16x = 16
x = 1

GenaCL600 [577]3 years ago

5 0

Answer:

x = ±sqrt(2)

Step-by-step explanation:

8x^2 - 5 = 11

Add 5 to each side

8x^2 - 5+5 = 11+5

8x^2 = 16

Divide each side by 8

8x^2 = 16/8

x^2 = 2

Take the square root of each side

sqrt(x^2) = ±sqrt(2)

x = ±sqrt(2)

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7 0

3 years ago

Use differentials to approximate the value of the expression. Compare your answer with that of a calculator. (Round your answers

Vesna [10]

Answer:

726.572699

Step-by-step explanation:

According to differentials

(x+Δx)³ = x³ + 3x²Δx + 3x(Δx)² + (Δx)³ (Using binomial expansion)

Using this formula to solve (8.99)³, this can also be written as;

(8.99)³ = (9-0.01)³ where

x = 9

Δx = -0.01

Substitute this vales into the differential expression above

(9+(-0.01))³ = 9³ + 3(9)²(-0.01) + 3(9)(-0.01)² + (-0.01)³

(9+(-0.01))³ = 729 + (243)(-0.01) + 27(0.0001) + (-0.000001)

(9+(-0.01))³ = 729-2.43+0.0027-0.000001

(9+(-0.01))³ = 726.572699

Hence 8.99³ = 726.572699 (Using differential)

Using calculator;

8.99³ = 726.572699

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