# How do you simplify (6) (3x-y) - (4)(2x+y)?

Nov 7, 2015

• Multiply the factors into each other using $x \left(a + b\right) = \left(a x + b x\right)$

This will give us the answer $10 x - 10 y \mathmr{and} 10 \left(x - y\right)$

#### Explanation:

To handle this type of multiplication, use this rule:
$x \left(a + b\right) = \left(a x + b x\right)$

This gives us:
$6 \left(3 x - y\right) - \left(4 \left(2 x + y\right)\right)$

Remember to put parentheses around the factors after a minus sign! If you don't you might end up with a different answer if you don't keep your tounge in your mouth.

Multiply the factors into the parentheses:

$\left(18 x - 6 y\right) - \left(8 x + 4 y\right)$

The first set of parentheses is positive, which results in no change of sign inside the parentheses. However, the second set of parentheses is negative (you can see this because of the minus sign). When this happens, you have to change the sign inside the parentheses. This gives us:

$18 x - 6 y - 8 x - 4 y$
$18 x - 8 x - 6 y - 4 y$
$10 x - 10 y$

Eventually 10(x-y)