How do you expand (4x-3)^2?

3 Answers
May 29, 2018

16x^2-24x+9

Explanation:

Given: (4x-3)^2

Use the binomial theorem for the second power, which we find that:

  • (a+b)^2=a^2+2ab+b^2

  • (a-b)^2=a^2-2ab+b^2

Here a=4x,b=3, and we use the second formula.

So, we get:

(4x-3)^2=(4x)^2-2*3*4x+3^2

=16x^2-24x+9

May 29, 2018

16x^2 - 24x +9

Explanation:

First let

a = 4x

b = -3

we use the formula

a^2 + 2ab + b^2

so
(4x)^2 + 2(4x)(-3) + (-3)^2

the result will be

16x^2 - 24x + 9

May 29, 2018

16x^2-24x+9

Explanation:

Given: (4x-3)^2

Write as: color(blue)((4x-3))color(green)( (4x-3) )

Multiply everything in the second bracket by everything in the first.

color(green)(color(blue)(4x)(4x-3)color(white)("ddd")color(blue)(-3)(4x-3)) larr notice the way the minus
color(white)("dddddddddddddddddddddddd")followed the color(blue)(3)

16x^2ubrace(-12xcolor(white)("ddd") -12x)+9

16x^2color(white)("dddd")-24xcolor(white)("dddd")+9