Question

Expand the expression (5x + 3)2, and write the result in standard form.

A.
25x2 + 9
B.
25x2 + 15x + 9
C.
25x2 + 24
D.
25x2 + 30x + 9

Answer 1

option D is correct

The result in standard form is,

`25x^2+30x+9`

Explanation:

The standard form of the equation is given by:

`y = Ax^2+Bx+C` where, A, B and C are the coefficient and x is the variable.

Using the identity rule:

`(a+b)^2 = a^2+2ab+b^2`

Expand the expression:

`(5x+3)^2`

Apply the identity rule:

`(5x)^2+2(5x)(3)+3^2`

⇒
`25x^2+30x+9`

The result in standard form is,
`25x^2+30x+9`

Therefore, the result in standard form is,
`25x^2+30x+9`

Answer 2

`(5x+3)^2\\\\\text{use}\ (a+b)^2=a^2+2ab+b^2\\\\=(5x)^2+2(5x)(3)+3^2\\\\=5^2x^2+30x+9\\\\=25x^2+30x+9\to D.`