Let a and b be rational numbers. Is a – b rational or irrational?
1 answer:
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Answer:
- x = -1/2(1 +√21) ≈ -2.79129
- x = -1/2(1 -√21) ≈ 1.79129
Step-by-step explanation:
We assume the middle term is supposed to be 4x.
We can remove a common factor of 4 to simplify this a bit.
x^2 +x -5 = 0
This is of the form
ax^2 +bx +c = 0
where a=1, b=1, c=-5.
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The <em>quadratic formula</em> gives the solutions as ...
Filling in the given coefficients, we have ...
x = (-1 ±√(1^2 -4·1·(-5)))/(2·1)
x = (-1±√21)/2
The solutions are x = -1/2(1 +√21) and -1/2(1 -√21).
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<em>If what you wrote is what you intend</em>, then the equation simplifies to 4x^2 -16 = 0.
Dividing by 4 and factoring the difference of squares gives ...
x^2 -4 = 0
(x -2)(x +2) = 0
These factors are zero (hence their product is 0) for the values x = 2 and x = -2.
The solutions are x=2 and x=-2.
An equation is formed of two equal expressions. The correct options are C, D, and E.
<h3>What is an equation?</h3>An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
The value of x in the given equation is,
Substitute the value of x in other option to check if the equations are equal are not. Therefore, the options can be written as,
A.) 18x - 15 = 72
18(4.5) - 15 = 66
Thus, this will not return the same value.
B.) 50x - 25 = 72
50(4.5) - 25 = 200
Thus, this will not return the same value.
C.) 18x - 9 = 72
18(4.5) - 9 = 72
Thus, this will return the same value.
D.) 3(6x - 3) = 72
3[6(4.5) - 3] = 72
Thus, this will return the same value.
E.) x = 4.5
Thus, this will return the same value.
Hence, the correct options are C, D, and E.
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Answer:
4
Step-by-step explanation:
Given that
Now,
This can be written as
[as
]
[ by using equation (i)]
=4
Hence,