a=4/3b

2a^2-3ab+b^2/a^2-b^2

=(a-b)(2a-b)/(a+b)(a-b)

=2a-b/a+b

=(2*4/3b-b)/(4/3b+b)

=(5/3)/(7/3)

=5/7

x^-6x+8y+y^+25=0

(x-3)^2+(y+4)^2=0

(x-3)^2=0

x=3

(y+4)^2=0

y=-4

2x-3y under the root symbol

Under the radical sign = 2*3-3(-4)

Under the root sign = 6+ 12

Under the root number 3 = 2