Answer:
B(7,10)
Step-by-step explanation:
[tex]M(5,7)=(x ,y)\\A(3,4)=(x_1,y_1)\\B(x_2,y_2)\\\\Endpoint ;\\x = \frac{x_1+x_2}{2}\\ \\5 = \frac{3+x_2}{2}\\ Cross\:Multiply\\5\times 2 =3+x_2\\10=3+x_2\\10-3 =x_2\\7=x_2\\\\\\y = \frac{y_1+y_2}{2} \\\\7 = \frac{4+y_2}{2}\\ Cross\:Multiply\\7\times 2 =4+y_2\\14 =4+y_2\\14-4 =y_2\\10 =y_2\\\\\\B(7,10)[/tex]