Question

Find the area of the triangle if A=1/2bh

Answer 1

A= 12x-4(3x+2)/2. 36x2+24x-12x-8. 36x2+12x-8/2. 18x2+6x-4.

Answer 2

Here the base is 12x - 4 and the height is 3x + 2, so let's plug these into the formula:

$\sf A=\dfrac{1}{2}bh$

$\sf A=\dfrac{1}{2}(12x-4)(3x+2)$

First distribute 1/2 into the first parenthesis, we do this by multiplying it to every term:

$\sf\dfrac{1}{2}\cdot 12x=6x$
$\sf\dfrac{1}{2}\cdot -4=-2$

So we have:

$\sf (6x-2)(3x+2)$

Distribute, multiply every term in the first parenthesis to every term in the second:

$\sf 6x\cdot 3x=18x^2$
$\sf 6x\cdot 2=12x$
$\sf -2\cdot 3x=-6x$
$\sf -2\cdot 2=-4$

So we're left with:

$\sf 18x^2+12x-6x-4$

Combine like terms(12x - 6x = 6x):

$\boxed{\sf 18x^2+6x-4}$