Answer:
[tex]\huge\boxed{-32a^2b+7a^2+3b^2-35ab-a+40b+3}[/tex]
Step-by-step explanation:
[tex]7b(2a^2+5a-7)\qquad|\text{use the distributive property}\\\\=(7b)(2a^2)+(7b)(5a)+(7b)(-7)=14a^2b+35ab-49b\\\\\\(7a^2-a+3)-3b(6a^2-b+3)\qquad|\text{use the distributive property}\\\\=7a^2-a+3+(-3b)(6a^2)+(-3b)(-b)+(-3b)(3)\\\\=7a^2-a+3-18a^2b+3b^2-9b[/tex]
Substraction
[tex](7a^2-a+3-18a^2b+3b^2-9b)-(14a^2b+35ab-49b)\\\\=7a^2-a+3-18a^2b+3b^2-9b-14a^2b-35ab+49b\\\\\text{combine like terms}\\\\=(-18a^2b-14a^2b)+7a^2+3b^2-35ab-a+(-9b+49b)+3\\\\=-32a^2b+7a^2+3b^2-35ab-a+40b+3[/tex]
