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4 votes
What is the value of the expression below when w = 3. 4w^2 - 7w - 8

2 Answers

6 votes

Answer:

7

Step-by-step explanation:

User Andrii Yurchuk
by
4.1k points
6 votes

Answer: w =(-40-√4320)/-34=(20+6√ 30 )/17= 3.110

w =(-40+√4320)/-34=(20-6√ 30 )/17= -0.757

Step-by-step explanation: The prime factorization of 4320 is

2•2•2•2•2•3•3•3•5

To be able to remove something from under the radical, there have to be 2 instances of it (because we are taking a square i.e. second root).

√ 4320 = √ 2•2•2•2•2•3•3•3•5 =2•2•3•√ 30 =

± 12 • √ 30

√ 30 , rounded to 4 decimal digits, is 5.4772

So now we are looking at:

w = ( -40 ± 12 • 5.477 ) / -34

Two real solutions:

w =(-40+√4320)/-34=(20-6√ 30 )/17= -0.757

or:

w =(-40-√4320)/-34=(20+6√ 30 )/17= 3.110

MY HEAD HURTS!

User Pouya Jabbarisani
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4.6k points