6. Which expression is equivalent to (7mn+2m-18nd)-(-3m-6mn+7nd) mn+5m-25nd 10mn-4m-11nd 10mn-m-25nd 13mn+5m-25nd

To find the expression equivalent to $(7mn+2m-18nd)-(-3m-6mn+7nd)$, we need to simplify the expression by combining like terms.<br /><br />Step 1: Remove the parentheses by distributing the negative sign to the terms inside the second set of parentheses.<br />$(7mn+2m-18nd) - (-3m-6mn+7nd) = 7mn + 2m - 18nd + 3m + 6mn - 7nd$<br /><br />Step 2: Combine like terms.<br />$7mn + 6mn + 2m + 3m - 18nd - 7nd = 13mn + 5m - 25nd$<br /><br />Therefore, the expression equivalent to $(7mn+2m-18nd)-(-3m-6mn+7nd)$ is $13mn+5m-25nd$.