## anonymous 5 years ago solve equation by square root property 3(x+7)^2=60

1. anonymous

browneez, divide through by 3 first to get$(x+7)^2=20$Then take the square root of both sides $\sqrt{(x+7)^2}=\pm \sqrt{20} \rightarrow x+7=\pm \sqrt{20} \rightarrow x=-7 \pm \sqrt{20}$Now, you have that $20=4 \times 5 = 2^2 \times 5$so that$\sqrt{20}=\sqrt{2^2 \times 5}=\sqrt{2^2}\times \sqrt{5}=2\sqrt{5}$so $x=-7 \pm 2\sqrt{5}$

2. anonymous

You have to take a 'plus or minus' on one side when you take the square root. We usually attach it to the number.

3. anonymous

thanks, the 3 on the outside of the() was throwing me off.