Sagot :
Answer:
1. 5x*x+5x*3
=5x²+15x
2. -4x*x²+4x*5x-4x*10
=-4x³+20x²-40
3. 12(2x+8)
=12*2x+12*8
= 24x+96
4. a*a+a*4+8*a+8*4
= a²+4a+8a+32
= a²+12a+32
5. 2a*a-2a*8-7*a+7*8
= 2a²-16a-7a+56
=2a²-23a+56
note that * means multiply by and double negatives result in postives