A) P (7 , Y1) ; Q ( - 5 , 2)
X1 = 7 ; Y1 = Y1 ; X2 = - 5 ; Y2 = 2 <img src="https://tex.z-dn.net/?f=d%3D%20%5Csqrt%7B%28X2%20-%20X1%29%5E%7B2%7D%2B%28Y2%20-%20Y1%29%5E%7B2%7D%7D%20" />
d = 13 Unidades
13 = <img src="https://tex.z-dn.net/?f=%5Csqrt%7B%28X2%20-%20X1%29%5E%7B2%7D%2B%28Y2%20-%20Y1%29%5E%7B2%7D%7D%20" />
13 = <img src="https://tex.z-dn.net/?f=%5Csqrt%7B%28-5%20-%207%29%5E%7B2%7D%2B%282%20-%20Y1%29%5E%7B2%7D%7D%20" /> (Elevo ambos terminos de la igualdad al cuadrado)
(13)² = ( - 12)² + (2 - Y1)²
169 = 144 + 4 - 4Y1 + Y1²
169 = 148 - 4Y1 + Y1²
0 = 148 - 169 - 4Y1 + Y1²
0 = - 21 - 4Y1 + Y1²
Y1² - 4Y1 - 21 = 0 (Ecuacion de segundo grado para Y1)
Donde : a = 1 ; b = - 4 ; c = - 21 <img src="https://tex.z-dn.net/?f=Y1%3D%5Cfrac%7B-b%5Cpm%20%5Csqrt%7Bb%5E2-4ac%7D%7D%7B2a%7D" />
<img src="https://tex.z-dn.net/?f=Y1%3D%5Cfrac%7B-%28-4%29%5Cpm%20%5Csqrt%7B%28-4%29%5E2-4%281%29%28-21%29%7D%7D%7B2%281%29%7D" />
<img src="https://tex.z-dn.net/?f=Y1%3D%5Cfrac%7B4%5Cpm%20%5Csqrt%7B16%2B84%7D%7D%7B2%7D" />
<img src="https://tex.z-dn.net/?f=Y1%3D%5Cfrac%7B4%5Cpm%20%5Csqrt%7B100%7D%7D%7B2%7D" />
<img src="https://tex.z-dn.net/?f=Y1%3D%5Cfrac%7B4%5Cpm%20%5C%2010%7D%7B2%7D" />
Y1(1) = [4 + 10] / 2 = 14 / 2 = 7
Y1(2) = [4 - 10] / 2 = - 6 / 2 = - 3
Vemos que Y1 puede tomar los dos Valores de 7 y - 3 y ambos cumplen con la distancia
P (7, 7) Q( - 5, 2) o P (7 , - 3) Q ( - 5, 2).
B) M : ( - 3, - 5) ; Q ( - 6, Y2)
<img src="https://tex.z-dn.net/?f=d%3D%20%5Csqrt%7B%28X2%20-%20X1%29%5E%7B2%7D%2B%28Y2%20-%20Y1%29%5E%7B2%7D%7D%20" />
d = √(73)
X1 = - 3 ; Y1 = - 5 ; X2 = - 6 ; Y2 = Y2
<img src="https://tex.z-dn.net/?f=%20%5Csqrt%7B73%7D%3D%20%5Csqrt%7B%28-6%20-%20%28-3%29%29%5E%7B2%7D%2B%28Y2%20-%20%28-5%29%29%5E%7B2%7D%7D%20%20" />
[img = 10]
[img = 11] (Elevo ambos terminos al cuadrado)
[img = 12]
73 = ( - 3)² + (Y2 + 5)²
73 = 9 + (Y2² + 10Y2 + 25)
73 = 9 + Y2² + 10Y2 + 25
73 = Y2² + 10Y2 + 34
0 = Y2² + 10Y2 + 34 - 73
0 = Y2² + 10Y2 - 39 (Ecuacion de segundo grado para Y2)
Donde : a = 1 ; b = 10 ; c = - 39
[img = 13]
[img = 14]
[img = 15]
[img = 16]
[img = 17]
Y2(1) = [ - 10 + 16] / 2 = 6 / 2 = 3
Y2(2) = [ - 10 - 16] / 2 = - 26 / 2 = - 13
Y2 = 3 o Y2 = - 13
Entonces los puntos pueden ser :
M( - 3, - 5) y Q( - 6 , 3) o M( - 3, - 5) y Q( - 6 , - 13)
Te anexo las graficas de las dos situaciones.