10 g cubed -8 g squared + 5 g - 14 times 10 g squared + 12 g

(10g^3 - 8g^2 + g - 14)(10g^2 + g)

Multiply eah term by 10g^2 and then add it to each term times g

100g^5 - 80g^4 + 10g^3 - 140g^2 + 10g^4 - 8g^3 + g^2 - 14g)

Combine like terms

100g ^5 - 80g^4 + 10g^4 + 10g^3 - 8g^3 - 140g^2 + g^2 - 14g

100g^5 - 70g^4 + 2g^3 - 139g^2 - 14g

100g^5 - 70g^4 + 2g^3 - 139g^2 - 14g

hope it helps :)

just sum

10 + 10 = 20