Answer:
[tex]10x^2+11x+7[/tex]
Step-by-step explanation:
Given the expression:
[tex]7x(5x+3)-(25x^2+10x-7)[/tex]
Use distributive property:
[tex]7x(5x+3)=7x\cdot 5x+7x\cdot 3=35x^2+21x\\ \\7x(5x+3)-(25x^2+10x-7)=35x^2+21x-(25x^2+10x-7)[/tex]
Open brackets:
[tex]35x^2+21x-(25x^2+10x-7)=35x^2+21x-25x^2-10x+7[/tex]
Combine the like terms:
[tex]35x^2+21x-25x^2-10x+7=(35x^2-25x^2)+(21x-10x)+7=10x^2+11x+7[/tex]