How do you solve ${{\left( -3-4x \right)}^{\dfrac{1}{2}}}-{{\left( -2-2x \right)}^{\dfrac{1}{2}}}=1$
Answer
626.7k+ views
Hint: We can solve the given equation by squaring both LHS and RHS , we may have to square both LHS and RHS again to find the value of x. We have to use the property ${{\left( {{a}^{\dfrac{1}{2}}} \right)}^{2}}=a$ . When we write some number power $\dfrac{1}{2}$ then the number must be positive to get a real result.
Complete step by step answer:
The given equation in the question is ${{\left( -3-4x \right)}^{\dfrac{1}{2}}}-{{\left( -2-2x \right)}^{\dfrac{1}{2}}}=1$
We can solve the above equation by squaring both sides , so squaring both sides we get
${{\left( {{\left( -3-4x \right)}^{\dfrac{1}{2}}}-{{\left( -2-2x \right)}^{\dfrac{1}{2}}} \right)}^{2}}=1$
$\Rightarrow \left( -3-4x \right)+\left( -2-2x \right)+2{{\left[ \left( -3-4x \right)\left( -2-2x \right) \right]}^{\dfrac{1}{2}}}=1$
$\Rightarrow -6x-5+2{{\left[ 8{{x}^{2}}+14x+6 \right]}^{\dfrac{1}{2}}}=1$
Adding 6x+5 in both LHS and RHS we get
$\Rightarrow 2{{\left[ 8{{x}^{2}}+14x+6 \right]}^{\dfrac{1}{2}}}=6x+6$
Diving both LHS and RHS by 2 and then squaring both sides we get
$\Rightarrow 8{{x}^{2}}+14x+6=9{{x}^{2}}+18x+9$
Further solving we get
$\Rightarrow {{x}^{2}}+4x+3=0$
Factoring the above quadratic equation we get
$\Rightarrow \left( x+3 \right)\left( x+1 \right)=0$
So the value of x can be -3 or -1
We can check our answers by putting it in the equation and check whether it satisfy or not
So putting x equal to -3 we get
${{\left( -3-4\times -3 \right)}^{\dfrac{1}{2}}}-{{\left( -2-2\times -3 \right)}^{\dfrac{1}{2}}}$
$\Rightarrow {{9}^{\dfrac{1}{2}}}-{{4}^{\dfrac{1}{2}}}=1$
So -3 is correct answer
Now putting x equal to -1 we get
${{\left( -3-4\times -1 \right)}^{\dfrac{1}{2}}}-{{\left( -2-2\times -1 \right)}^{\dfrac{1}{2}}}$
$\Rightarrow {{1}^{\dfrac{1}{2}}}-0=1$
So -1 is also correct answer
Note: In mathematics the square root of any positive real number can not be a negative number. For example the solution of ${{x}^{2}}=9$ can be 3 or -3 but the value of the square root of 9 is not -3 , it is only 3. So write the solution or roots of the equation ${{x}^{2}}=9$ is $\pm \sqrt{9}$ which is 3 and -3.
Complete step by step answer:
The given equation in the question is ${{\left( -3-4x \right)}^{\dfrac{1}{2}}}-{{\left( -2-2x \right)}^{\dfrac{1}{2}}}=1$
We can solve the above equation by squaring both sides , so squaring both sides we get
${{\left( {{\left( -3-4x \right)}^{\dfrac{1}{2}}}-{{\left( -2-2x \right)}^{\dfrac{1}{2}}} \right)}^{2}}=1$
$\Rightarrow \left( -3-4x \right)+\left( -2-2x \right)+2{{\left[ \left( -3-4x \right)\left( -2-2x \right) \right]}^{\dfrac{1}{2}}}=1$
$\Rightarrow -6x-5+2{{\left[ 8{{x}^{2}}+14x+6 \right]}^{\dfrac{1}{2}}}=1$
Adding 6x+5 in both LHS and RHS we get
$\Rightarrow 2{{\left[ 8{{x}^{2}}+14x+6 \right]}^{\dfrac{1}{2}}}=6x+6$
Diving both LHS and RHS by 2 and then squaring both sides we get
$\Rightarrow 8{{x}^{2}}+14x+6=9{{x}^{2}}+18x+9$
Further solving we get
$\Rightarrow {{x}^{2}}+4x+3=0$
Factoring the above quadratic equation we get
$\Rightarrow \left( x+3 \right)\left( x+1 \right)=0$
So the value of x can be -3 or -1
We can check our answers by putting it in the equation and check whether it satisfy or not
So putting x equal to -3 we get
${{\left( -3-4\times -3 \right)}^{\dfrac{1}{2}}}-{{\left( -2-2\times -3 \right)}^{\dfrac{1}{2}}}$
$\Rightarrow {{9}^{\dfrac{1}{2}}}-{{4}^{\dfrac{1}{2}}}=1$
So -3 is correct answer
Now putting x equal to -1 we get
${{\left( -3-4\times -1 \right)}^{\dfrac{1}{2}}}-{{\left( -2-2\times -1 \right)}^{\dfrac{1}{2}}}$
$\Rightarrow {{1}^{\dfrac{1}{2}}}-0=1$
So -1 is also correct answer
Note: In mathematics the square root of any positive real number can not be a negative number. For example the solution of ${{x}^{2}}=9$ can be 3 or -3 but the value of the square root of 9 is not -3 , it is only 3. So write the solution or roots of the equation ${{x}^{2}}=9$ is $\pm \sqrt{9}$ which is 3 and -3.
Recently Updated Pages
If x a + bt + ct2 where x is in meters and t is in class 11 physics CBSE

A car covers the first half distance between two places class 11 physics CBSE

The resultant of two vectors overrightarrow P and overrightarrow class 11 physics CBSE

Find the value of cos 135 class 11 maths CBSE

A mass M is held in place by an applied force F and class 11 physics CBSE

A solution of glucose in water is labelled as 10 dfracwv class 11 chemistry CBSE

Trending doubts
One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

Find the value of the expression given below sin 30circ class 11 maths CBSE

What do you mean by retardation What is its SI uni class 11 physics CBSE

Draw a diagram of nephron and explain its structur class 11 biology CBSE

10 examples of friction in our daily life

Difference between physical and chemical change class 11 chemistry CBSE

