Final answer:
To find the expression that can be subtracted from 21x+14 to get a specific difference, we simplify and rearrange the terms to obtain the subtracted expression.
Step-by-step explanation:
To find what can be subtracted from the expression 21x+14 to get a difference of -4x²+5x+3, we can subtract the two expressions.
So, (21x+14) - (-4x²+5x+3) (distributing the negative sign) becomes 21x +14 + 4x² - 5x - 3.
Simplifying further, we rearrange the terms to get 4x² + 21x - 5x + 14 - 3.
Combining like terms, we have 4x² + 16x + 11.
Therefore, subtracting 4x² + 16x + 11 from 21x+14 gives the difference -4x²+5x+3.