Question

Show that x = — 3 is a solution of 2x2 + 5x –3 = 0.

Answer 1

Note:

• The possible values of unknown (variable) for which the equation is satisfied are called its solutions or roots .

• If x = a is a solution of any equation in x , then it must satisfy the given equation otherwise it's not a solution (root) of the equation.

Solution:

Here,

The given equation is : 2x² + 5x - 3 = 0 ------(1)

Let's check whether x = -3 is a solution of eq-(1) .

Putting x = -3 in eq-(1) , we have ;

=> 2•(-3)² + 5•(-3) - 3 = 0

=> 18 - 15 - 3 = 0

=> 18 - 18 = 0

=> 0 = 0 (which is true)

Since , eq-(1) is satisfied by x = -3 , thus x = -3 is a solution of eq-(1) .

Hence proved.

Answer 2

$\huge{\boxed{\red{Answer}}}$

$\large{\underline{\pink{Required\;to\;find}}}$

$Whether\;-3\;is\;a\;solution\;of\;equation\\2{x}^{2}+5x-3=0$

$\large{\underline{\purple{Verifying\;-3\;as\;a\;solution}}}$

• Substituting $-3$ in the equation

• $2{x}^{2}+5x-3=0$

• $2({-3}^{2})+5(-3)-3=0$

• $18-15-3=0$

• 0=0

$\boxed{\red{Therefore\;-3\;is\;solution\;of\;given\;equation}}$

$\huge{\boxed{\blue{NOTE}}}$

• If 'a' is a root of a given equation then it must satisfy the given equation
• I have used the above statement to verify -3 as root of given equation