Question

Using identities, evaluate the following: (3x -4)(3x + 5)​

Answer 1

• We have to evaluate the above expression by using the given data.

            Given data:- $(3x-4)(3x+5).$

            To find:- Value of the expression.

            Solution:-

• We know that factorization means reducing any algebraic or quadratic equation.

• Steps to solve quadratic equations,

• Step 1: Rearrange the given quadratic so that is it equal to zero.

• Step 2: Factorise the quadratic.

• Step 3: Form two linear equations.

• Step 4: Solve the equations to find the roots of the equation.

        Therefore,

       We can apply an identity,

       $(a+b)(c+d)=a c+a d+b c+b d.$

       Therefore,

        $(3x-4)(3x+5)\\=>3 x \times 3 x+3 x \times 5-4 \times 3 x-4 \times 5\\=>9 x^{2}+3 x-20.$

       Hence we will get $(3x-4)(3x+5)=9 x^{2}+3 x-20.$