Plz solve Q5 and Q7 in a paper only i need handwritten ans with proper steps and explanation

Dear Student 
3(9+7x)-(2-x)(9+7x)
=(9+7x)( 3-(2-x))
=(9+7x)(3-2+x)
=(9+7x)(1+x)
=9+9x+7x+7x²
=7x² + 16x+9

Kindly ask the remaining questions in separate threads 

Regards