How do I simplify (6x-10x^2+3)-(5x^2+3x-4) ???

Step-by-step explanation:

6x-10x^2+3-(5x^2+3x-4)

when there is a - in front of an expression in (), change the sign of each term in the expression

6x-10x^2+3-5x^2-3x+4

now collect like terms

3x-10x^2+3-5x^2+4

3x-15x^2+3+4

3x-15x^2+7

now use the commutative property to reorder the terms

-15x^2+3x+7

=-15x^2+3x+7

if you mean

then it's c. 8, -7/3

but if you mean

then it is

question is incomplete.