We've already learnt about the concept of negative numbers and how to simplify and evaluate expressions with directed numbers.
Now we are going to look at working with algebraic expressions that have positive and negative terms.
There are a few important things to remember when working with directed numbers:
Example  

$\left(2f\right)\times5g=10fg$(−2f)×5g=−10fg 

$6\times\left(7c\right)=42c$−6×(−7c)=42c 

$3\left(2a\right)$3−(−2a) is the same as $3+2a$3+2a 

$h+\left(3\right)$h+(−3) is the same as $h3$h−3 
It may help to visualise a number line when you are working with directed numbers. Negatives go to the left down the number line and positives go up to the right down the number line.
Simplify: $2m9m$−2m−9m
Simplify the expression: $3x\left(4x\right)2x$3x−(−4x)−2x
Simplify the expression $\frac{10x}{3x}$10x3x