Question 4 (1 point) Multiply. (7m+9)^2 a 7m^2+81 b 49m^2+81 C. 7m^2+126m+81 d 49m^2+126m+81

To multiply $(7m+9)^{2}$, we can use the formula for the square of a binomial: $(a+b)^{2} = a^{2} + 2ab + b^{2}$.<br /><br />In this case, $a = 7m$ and $b = 9$. Plugging these values into the formula, we get:<br /><br />$(7m+9)^{2} = (7m)^{2} + 2(7m)(9) + 9^{2}$<br /><br />Simplifying further, we have:<br /><br />$(7m+9)^{2} = 49m^{2} + 126m + 81$<br /><br />Therefore, the correct answer is d) $49m^{2} + 126m + 81$.