Questions Related to maths

Multiple choice maths unchanging relations algebra aid introduction to unknowns measures and relations

Consider the polynomial $\dfrac{x^{3}+2x+1}{5}-\dfrac{7}{2}x^{2}-x^{6}$. 

The constant term is:

  1. $\dfrac{1}{7}$
  2. $\dfrac{1}{5}$
  3. $\dfrac{1}{2}$
  4. $\dfrac{1}{3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$\cfrac { { x^{ 3 }+2x+1 } }{ 5 } -\cfrac { 7 }{ 2 } x^ 2-x^ 6$
$=\cfrac { { x^{ 3 }+2x+1 } }{ 5 } -\cfrac { 7 }{ 2 } x^ 2-x^ 6$
$=-x^ 6+\cfrac { x^{ 3 } }{ 5 } -\cfrac { 7x^ 2 }{ 2 } +\cfrac { 2x }{ 5 } +\cfrac { 1 }{ 5 }$
So, the constant term= $\cfrac { 1 }{ 5 }$

Multiple choice maths unchanging relations algebra aid introduction to unknowns measures and relations

Which of the following expressions is a polynomial in one variable?

  1. $x+\dfrac {2}{3}+3$
  2. $3\sqrt {x}+\dfrac {2}{\sqrt {x}}+5$
  3. $\sqrt {2x^{2}}-\sqrt {3x}+6$
  4. $x^{10}+y^{5}+8$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A polynomial in one variable must have non-negative integer exponents for the variable. Option A (x + 2/3 + 3) is a polynomial in x, whereas the others involve square roots of variables or multiple variables.

Multiple choice maths unchanging relations algebra aid introduction to unknowns measures and relations

If $\dfrac{2+3}{x}=\dfrac{2+x}{3}$
What one value for $x$ can be correctly entered into the answer grid?

  1. -5

  2. 3

  3. -3

  4. 2

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given, $\dfrac{2+3}{x}=\dfrac{2+x}{3}$

$\Rightarrow 2x+x^2=15$
$\Rightarrow x^2+2x-15=0$
$\Rightarrow x^2+5x-3x-15=0$
$\Rightarrow x(x+5)-3(x+5)=0$
$\Rightarrow (x+5)(x-3)=0$
$\Rightarrow x=-5,3$
Value of $x$ is not negative, so $x=3$.