Tag: maths

Questions Related to maths

If $\sqrt { 1+\dfrac { x }{ 289 }  } =1\dfrac { 1 }{ 17 }$ then $x=$

  1. $1$

  2. $13$

  3. $35$

  4. $15$


Correct Option: C
Explanation:

We have,

$\sqrt{1+\dfrac{x}{289}}=1\dfrac{1}{17}$

$\sqrt{\dfrac{289+x}{289}}=\dfrac{18}{17}$

 

On squaring both sides, we get

$ {{\left( \sqrt{\dfrac{289+x}{289}} \right)}^{2}}={{\left( \dfrac{18}{17} \right)}^{2}} $

$ \dfrac{289+x}{289}=\dfrac{324}{289} $

$ 289+x=324 $

$ x=324-289 $

$ x=35 $

 

Hence, this is the answer.

Solve for $x$:-
$\dfrac{{2x - 1}}{2}\,\,\, - \dfrac{{x + 3}}{3}\,\, = \dfrac{{x - 2}}{5}$

  1.  $x=\dfrac{5}{14}$

  2.  $x=\dfrac{3}{14}$

  3.  $x=\dfrac{33}{14}$

  4. None of these


Correct Option: C
Explanation:

$\dfrac{{2x - 1}}{2}\,\,\, - \dfrac{{x + 3}}{3}\,\, = \dfrac{{x - 2}}{5}\Rightarrow \dfrac{6x-3-2x-6}{6}=\dfrac{x-2}{5}\Rightarrow 20x-45=6x-12\Rightarrow 14x=33\Rightarrow x=\dfrac{33}{14}$

If $\sqrt{10+ \sqrt{25+ \sqrt{x+ \sqrt{154+ \sqrt{225}}}}} = 4$ find the value of $x$

  1. 110

  2. 108

  3. 100

  4. 114


Correct Option: B
Explanation:

We have,

$\sqrt {10+\sqrt {25+\sqrt {x+\sqrt{154+\sqrt{225}}}}}=4$
$\Rightarrow \sqrt {10+\sqrt {25+\sqrt {x+\sqrt{154+15}}}}=4$
$\Rightarrow \sqrt {10+\sqrt {25+\sqrt {x+\sqrt{169}}}}=4$
$\Rightarrow \sqrt {10+\sqrt {25+\sqrt {x+13}}}=4$
On squaring both sides, we get
$10+\sqrt {25+\sqrt {x+13}}=16$
$\sqrt {25+\sqrt {x+13}}=6$
On squaring both sides, we get
$25+\sqrt {x+13}=36$
$\Rightarrow \sqrt {x+13}=11$
On squaring both sides, we get
$x+13=121$
$x=121-13=108$
Hence, $x=108$

If $x(5\, -\, a)\, =\, 10\, -\, x^{2}$ and x = 2, find the value of 'a'.

  1. $1$

  2. $8$

  3. $4$

  4. $2$


Correct Option: D
Explanation:

$
x(5-a)\quad =\quad 10-{ x }^{ 2 }\ x\quad =\quad 2\ So\ 2(5-a)\quad =\quad 10\quad -{ 2 }^{ 2 }\ 10\quad -\quad 2a\quad =\quad 10-4\ -2a\quad =\quad -4\ a\quad =\quad 2\ 
$

Solve the following equation: 

$(x\, -\, 2)^{2}\, =\, (x\, +\, 1)\, (x\, -\, 1)$

  1. $1.5$

  2. $1.75$

  3. $2.25$

  4. $1.25$


Correct Option: D
Explanation:

Given, $(x-2)^2=(x+1)(x-1)$

$\Rightarrow x^2-4x+4=x^2-1$ .... Using $(a-b)(a+b)=a^2-b^2$
$\Rightarrow -4x+4=-1$
$\Rightarrow -4x=-5$
$\Rightarrow x=\dfrac {5}{4}=1.25$

Solve for $x$ : $\sqrt[3]{x}\,- 4\, =\, 0$

  1. $64$

  2. $36$

  3. $81$

  4. $49$


Correct Option: A
Explanation:

$\displaystyle \sqrt[3]{x}\,- 4\, =\, 0\, \Rightarrow\, \sqrt[3]{x}\, =\, 4$.
$\Rightarrow\, x\, =\, 4^{3}\, =\, 64$

Solve for $x$ : $5\, -\, \sqrt{x}\, =\, 0$

  1. $25$

  2. $54$

  3. $15$

  4. $20$


Correct Option: A
Explanation:
Given, $5 - \sqrt { x }  = 0$
$ \sqrt { x }  = 5$
Squaring on both sides, we get
$ x = { 5 }^{ 2 } = 25$

Simplify: 
$\displaystyle 6x-\left( -4y-8x \right) $

  1. $2x+y$

  2. $14x+4y$

  3. $12x+3y$

  4. $15x+5y$


Correct Option: B
Explanation:

On simplifying, we have

$\displaystyle 6x-\left( -4y-8x \right) =6x+4y+8x$
$=14x+4y$
Hence simplified form of the given expression is $14x+4y$.

Simplify: 
$\displaystyle x-\left[ y-{ x-\left( y-1 \right) -2x}  \right] $

  1. $2y+1$

  2. $-2y+1$

  3. $2x+y-1$

  4. $2x-y-1$


Correct Option: B
Explanation:

On simplified, we have

$\displaystyle x-\left[ y-{ x-\left( y-1 \right) -2x}  \right] $
$=x-\left[ y-{ x-y+1-2x}  \right] $
=$\displaystyle x-\left[ y-{ -x-y+1}  \right] =x-\left[ y+x+y-1 \right] $
=$\displaystyle x-\left[ 2y+x-1 \right] =x-2y-x+1=-2y+1$
Hence, simplified form of the given expression is $-2y+1$.

Number of variables in a simple linear equation

  1. Two

  2. One

  3. 0

  4. None


Correct Option: B
Explanation:

A linear equation can comprise of many variables. The most simple linear equation is in $one$ variable ,i.e, $ax+b=0$.