We've already learnt about the concept of negative numbers and how to simplify and evaluate expressions with positive and negative 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 positive and negative 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 positive and negative 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
Multiply a polynomial by a monomial involving the same variable to give results up to degree three using a variety of tools