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Hi can someone help me here​

Hi can someone help me here​-example-1
User Laszlo Korte
by
3.2k points

2 Answers

21 votes
21 votes

Answer:

see explanation

Explanation:


(x+2)/(3) -
(2x-4)/(2) = 0

multiply through by 6 ( the LCM of 3 and 2 ) to clear the fractions

2(x + 2) - 3(2x - 4) = 0 ← distribute parenthesis on left side and simplify

2x + 4 - 6x + 12 = 0

- 4x + 16 = 0 ( subtract 16 from both sides )

- 4x = - 16 ( divide both sides by - 4 )

x = 4

------------------------------------------------------------


(5x)/(2) +
(x-2)/(8) = 2 ( multiply through by 8 to clear the fractions )

4(5x) + x - 2 = 16

20x + x - 2 = 16

21x - 2 = 16 ( add 2 to both sides )

21x = 18 ( divide both sides by 21 )

x =
(18)/(21) =
(6)/(7)

-----------------------------------------------------------


(x-5)/(4) -
(3x-1)/(5) = -
(3)/(2)

multiply through by 20 ( the LCM of 4, 5, 2 ) to clear the fractions

5(x - 5) - 4(3x - 1) = - 30 ← distribute parenthesis on left side and simplify

5x - 25 - 12x + 4 = - 30

- 7x - 21 = - 30 ( add 21 to both sides )

- 7x = - 9 ( divide both sides by - 7 )

x =
(9)/(7)

-------------------------------------------------------------


(1)/(x-1) +
(1)/(x+1) =
(4x+2)/(x^2-1) ← x² - 1 is a difference of squares , then


(1)/(x-1) +
(1)/(x+1) =
(4x+2)/((x-1)(x+1))

multiply through by (x - 1)(x + 1) to clear the fractions

x + 1 + x - 1 = 4x + 2

2x = 4x + 2 ( subtract 4x from both sides )

- 2x = 2 ( divide both sides by - 2 )

x = - 1

If we substitute this value back into the original equation, we find


(1)/(-1-1) +
(1)/(-1+1) =
(4(-1)+2)/((-1)^2-1)


(1)/(-2) +
(1)/(0) =
(-2)/(1-1)


(1)/(-2) +
(1)/(0) =
(-2)/(0)

division by zero is undefined

thus x = - 1 is an extraneous solution

the equation has no solution

User Joshua Gilman
by
3.1k points
26 votes
26 votes

Answer:


\textsf{1.} \quad x=4


\textsf{2.} \quad x=(6)/(7)


\textsf{3.} \quad x=(9)/(7)


\textsf{4.} \quad \textsf{No solution}

Explanation:

Question 1

Given equation:


(x+2)/(3)-(2x-4)/(2)=0


\textsf{Add \; $(2x-4)/(2)$ \; to both sides of the equation}:


\implies (x+2)/(3)-(2x-4)/(2)+(2x-4)/(2)=0+(2x-4)/(2)


\implies (x+2)/(3)=(2x-4)/(2)

Cross multiply:


\implies 2(x+2)=3(2x-4)


\implies 2x+4=6x-12

Subtract 2x from both sides:


\implies 2x+4-2x=6x-12-2x


\implies 4=4x-12

Add 12 to both sides:


\implies 4+12=4x-12+12


\implies 16=4x


\implies 4x=16

Divide both sides by 4:


\implies (4x)/(4)=(16)/(4)


\implies x=4

--------------------------------------------------------------------------

Question 2

Given equation:


(5x)/(2)+(x-2)/(8)=2

Multiply the numerator and denominator of the first fraction by 4:


\implies (5x \cdot 4)/(2\cdot 4)+(x-2)/(8)=2


\implies (20x)/(8)+(x-2)/(8)=2


\textsf{Apply the fraction rule} \quad (a)/(c)+(b)/(c)=(a+b)/(c):


\implies (20x+x-2)/(8)=2


\implies (21x-2)/(8)=2

Multiply both sides by 8:


\implies ((21x-2) \cdot 8)/(8)=2 \cdot 8


\implies 21x-2=16

Add 2 to both sides:


\implies 21x-2+2=16+2


\implies 21x=18

Divide both sides by 21:


\implies (21x)/(21)=(18)/(21)


\implies x=(18)/(21)

Reduce the fraction by dividing the numerator and denominator by 3:


\implies x=(18 / 3)/(21 / 3)


\implies x=(6)/(7)

--------------------------------------------------------------------------

Question 3

Given equation:


(x-5)/(4)-(3x-1)/(5)=-(3)/(2)

Multiply the numerator and denominator of the first fraction by 5, and the numerator and denominator of the second fraction by 4:


\implies ((x-5) \cdot 5)/(4\cdot 5)-((3x-1)\cdot 4)/(5\cdot 4)=-(3)/(2)


\implies (5x-25)/(20)-(12x-4)/(20)=-(3)/(2)


\textsf{Apply the fraction rule} \quad (a)/(c)-(b)/(c)=(a-b)/(c):


\implies (5x-25-(12x-4))/(20)=-(3)/(2)


\implies (5x-25-12x+4)/(20)=-(3)/(2)


\implies (-7x-21)/(20)=-(3)/(2)

Cross multiply:


\implies 2(-7x-21)=-3(20)


\implies -14x-42=-60

Add 42 to both sides:


\implies -14x-42+42=-60+42


\implies -14x=-18

Divide both sides by -14:


\implies (-14x)/(-14)=(-18)/(-14)


\implies x=(18)/(14)

Reduce the fraction by dividing the numerator and denominator by 2:


\implies x=(18 / 2)/(14 / 2)


\implies x=(9)/(7)

--------------------------------------------------------------------------

Question 4

Given equation:


(1)/(x-1)+(1)/(x+1)=(4x+2)/(x^2-1)

Factor the denominator of the fraction on the right side of the equation:


\implies (1)/(x-1)+(1)/(x+1)=(4x+2)/((x+1)(x-1))

Multiply the numerator and denominator of the first fraction by (x+1), and the numerator and denominator of the second fraction by (x-1):


\implies (x+1)/((x+1)(x-1))+(x-1)/((x+1)(x-1))=(4x+2)/((x+1)(x-1))


\textsf{Apply the fraction rule} \quad (a)/(c)+(b)/(c)=(a+b)/(c):


\implies (x+1+x-1)/((x+1)(x-1))=(4x+2)/((x+1)(x-1))


\implies (2x)/((x+1)(x-1))=(4x+2)/((x+1)(x-1))

Multiply both sides by (x+1)(x-1):


\implies (2x(x+1)(x-1))/((x+1)(x-1))=((4x+2)((x+1)(x-1))/((x+1)(x-1))


\implies 2x=4x+2

Subtract 4x from both sides:


\implies 2x-4x=4x+2-4x


\implies -2x=2

Divide both sides by -2:


\implies (-2x)/(-2)=(2)/(-2)


\implies x=-1

However, if we substitute x = -1 into the original equation we get:


\implies (1)/((-1)-1)+(1)/((-1)+1)=(4(-1)+2)/((-1)^2-1)


\implies -(1)/(2)+(1)/(0)=(-2)/(0)

A number divided by zero is undefined. Therefore, there is no solution for this equation.

User Sanzio Angeli
by
3.4k points