Question 1177996

This is my second assign. 
Please help me solve this. Thank you again in advance
[5(2a-b)-3][5(2a-b)+3]
<pre>[5(2a - b) - 3][5(2a - b) + 3] = {{{system((5(2a - b))^2 - 3^2, (10a - 5b)^2 
 - 9, highlight(highlight_green(100a^2 - 100ab + 25b^2 - 9)))}}}