For a) is just the distance formula
![\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) A&({{ x}}\quad ,&{{ 1}})\quad % (c,d) B&({{ -4}}\quad ,&{{ 1}}) \end{array}\qquad % distance value \begin{array}{llll} d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2} \\\\\\ \sqrt{8} = \sqrt{({{ -4}}-{{ x}})^2 + (1-1)^2} \end{array}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bdistance%20between%202%20points%7D%5C%5C%20%5Cquad%20%5C%5C%0A%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AA%26%28%7B%7B%20x%7D%7D%5Cquad%20%2C%26%7B%7B%201%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AB%26%28%7B%7B%20-4%7D%7D%5Cquad%20%2C%26%7B%7B%201%7D%7D%29%0A%5Cend%7Barray%7D%5Cqquad%20%0A%25%20%20distance%20value%0A%5Cbegin%7Barray%7D%7Bllll%7D%0A%0Ad%20%3D%20%5Csqrt%7B%28%7B%7B%20x_2%7D%7D-%7B%7B%20x_1%7D%7D%29%5E2%20%2B%20%28%7B%7B%20y_2%7D%7D-%7B%7B%20y_1%7D%7D%29%5E2%7D%0A%5C%5C%5C%5C%5C%5C%0A%5Csqrt%7B8%7D%20%3D%20%5Csqrt%7B%28%7B%7B%20-4%7D%7D-%7B%7B%20x%7D%7D%29%5E2%20%2B%20%281-1%29%5E2%7D%0A%5Cend%7Barray%7D)
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for b) is also the distance formula, just different coordinates and distance
![\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) A&({{ -7}}\quad ,&{{ y}})\quad % (c,d) B&({{ -3}}\quad ,&{{ 4}}) \end{array}\ \ \begin{array}{llll} d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2} \\\\\\ 4\sqrt{2} = \sqrt{(-3-(-7))^2+(4-y)^2} \end{array}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bdistance%20between%202%20points%7D%5C%5C%20%5Cquad%20%5C%5C%0A%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AA%26%28%7B%7B%20-7%7D%7D%5Cquad%20%2C%26%7B%7B%20y%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AB%26%28%7B%7B%20-3%7D%7D%5Cquad%20%2C%26%7B%7B%204%7D%7D%29%0A%5Cend%7Barray%7D%5C%20%5C%20%0A%5Cbegin%7Barray%7D%7Bllll%7D%0A%0Ad%20%3D%20%5Csqrt%7B%28%7B%7B%20x_2%7D%7D-%7B%7B%20x_1%7D%7D%29%5E2%20%2B%20%28%7B%7B%20y_2%7D%7D-%7B%7B%20y_1%7D%7D%29%5E2%7D%0A%5C%5C%5C%5C%5C%5C%0A4%5Csqrt%7B2%7D%20%3D%20%5Csqrt%7B%28-3-%28-7%29%29%5E2%2B%284-y%29%5E2%7D%0A%5Cend%7Barray%7D)
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for c) well... we know AB = BC.... we do have the coordinates for A and B
so... find the distance for AB, that is
![\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) A&({{ -3}}\quad ,&{{ 0}})\quad % (c,d) B&({{ 5}}\quad ,&{{ -2}}) \end{array}\qquad % distance value \begin{array}{llll} d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}\\\\ d=\boxed{?} \end{array}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bdistance%20between%202%20points%7D%5C%5C%20%5Cquad%20%5C%5C%0A%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AA%26%28%7B%7B%20-3%7D%7D%5Cquad%20%2C%26%7B%7B%200%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AB%26%28%7B%7B%205%7D%7D%5Cquad%20%2C%26%7B%7B%20-2%7D%7D%29%0A%5Cend%7Barray%7D%5Cqquad%20%0A%25%20%20distance%20value%0A%5Cbegin%7Barray%7D%7Bllll%7D%0A%0Ad%20%3D%20%5Csqrt%7B%28%7B%7B%20x_2%7D%7D-%7B%7B%20x_1%7D%7D%29%5E2%20%2B%20%28%7B%7B%20y_2%7D%7D-%7B%7B%20y_1%7D%7D%29%5E2%7D%5C%5C%5C%5C%0Ad%3D%5Cboxed%7B%3F%7D%0A%0A%5Cend%7Barray%7D)
now.. whatever that is, is = BC, so the distance for BC is
![\bf \textit{distance between 2 points}\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) B&({{ 5}}\quad ,&{{ -2}})\quad % (c,d) C&({{ -13}}\quad ,&{{ y}}) \end{array}\qquad % distance value \begin{array}{llll} d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}\\\\ d=BC\\\\ BC=\boxed{?} \end{array}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bdistance%20between%202%20points%7D%5C%5C%20%5Cquad%20%5C%5C%0A%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AB%26%28%7B%7B%205%7D%7D%5Cquad%20%2C%26%7B%7B%20-2%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AC%26%28%7B%7B%20-13%7D%7D%5Cquad%20%2C%26%7B%7B%20y%7D%7D%29%0A%5Cend%7Barray%7D%5Cqquad%20%0A%25%20%20distance%20value%0A%5Cbegin%7Barray%7D%7Bllll%7D%0A%0Ad%20%3D%20%5Csqrt%7B%28%7B%7B%20x_2%7D%7D-%7B%7B%20x_1%7D%7D%29%5E2%20%2B%20%28%7B%7B%20y_2%7D%7D-%7B%7B%20y_1%7D%7D%29%5E2%7D%5C%5C%5C%5C%0Ad%3DBC%5C%5C%5C%5C%0ABC%3D%5Cboxed%7B%3F%7D%0A%0A%5Cend%7Barray%7D)
so... whatever distance you get for AB, set it equals to BC, BC will be in "y-terms" since the C point has a variable in its ordered points
so.. .solve AB = BC for "y"
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now d) we know M and N are equidistant to P, that simply means that P is the midpoint of the segment MN
so use the midpoint formula
![\bf \textit{middle point of 2 points }\\ \quad \\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) M&({{-2}}\quad ,&{{ 1}})\quad % (c,d) N&({{ x}}\quad ,&{{ 1}}) \end{array}\qquad % coordinates of midpoint \left(\cfrac{{{ x_2}} + {{ x_1}}}{2}\quad ,\quad \cfrac{{{ y_2}} + {{ y_1}}}{2} \right)=P \\\\\\ ](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bmiddle%20point%20of%202%20points%20%7D%5C%5C%20%5Cquad%20%5C%5C%0A%5Cbegin%7Barray%7D%7Blllll%7D%0A%26x_1%26y_1%26x_2%26y_2%5C%5C%0A%25%20%20%28a%2Cb%29%0AM%26%28%7B%7B-2%7D%7D%5Cquad%20%2C%26%7B%7B%201%7D%7D%29%5Cquad%20%0A%25%20%20%28c%2Cd%29%0AN%26%28%7B%7B%20x%7D%7D%5Cquad%20%2C%26%7B%7B%201%7D%7D%29%0A%5Cend%7Barray%7D%5Cqquad%0A%25%20%20%20coordinates%20of%20midpoint%20%0A%5Cleft%28%5Ccfrac%7B%7B%7B%20x_2%7D%7D%20%2B%20%7B%7B%20x_1%7D%7D%7D%7B2%7D%5Cquad%20%2C%5Cquad%20%5Ccfrac%7B%7B%7B%20y_2%7D%7D%20%2B%20%7B%7B%20y_1%7D%7D%7D%7B2%7D%20%5Cright%29%3DP%0A%5C%5C%5C%5C%5C%5C%0A)
![\bf \left(\cfrac{{{ x_2}} + {{ x_1}}}{2}\quad ,\quad \cfrac{{{ y_2}} + {{ y_1}}}{2} \right)=(1,4)\implies \begin{cases} \cfrac{{{ x_2}} + {{ x_1}}}{2}=1\leftarrow \textit{solve for "x"}\\\\ \cfrac{{{ y_2}} + {{ y_1}}}{2}=4 \end{cases}](https://tex.z-dn.net/?f=%5Cbf%20%5Cleft%28%5Ccfrac%7B%7B%7B%20x_2%7D%7D%20%2B%20%7B%7B%20x_1%7D%7D%7D%7B2%7D%5Cquad%20%2C%5Cquad%20%5Ccfrac%7B%7B%7B%20y_2%7D%7D%20%2B%20%7B%7B%20y_1%7D%7D%7D%7B2%7D%20%5Cright%29%3D%281%2C4%29%5Cimplies%20%0A%5Cbegin%7Bcases%7D%0A%5Ccfrac%7B%7B%7B%20x_2%7D%7D%20%2B%20%7B%7B%20x_1%7D%7D%7D%7B2%7D%3D1%5Cleftarrow%20%5Ctextit%7Bsolve%20for%20%22x%22%7D%5C%5C%5C%5C%0A%5Ccfrac%7B%7B%7B%20y_2%7D%7D%20%2B%20%7B%7B%20y_1%7D%7D%7D%7B2%7D%3D4%0A%5Cend%7Bcases%7D)
now, for d), you can also just use the distance formula, find the distance for MP, then since MP = PN, find the distance for PN in x-terms and then set it to equal to MP and solve for "x"