Question

1.若4x-3y=0,且x=0,y≠0,求4x+5y分之4x-5y

Answer 1

1

4x-3y=0

x/y=3/4

（4x-5y）/（4x+5y）=(4x/y-5)/(4x/y+5)=-1/4

2

3x-6=5y

4y+15+x=0

x=-3,y=-3

x+y=-6

3

x+y=8

2x+2y=k=2(x+y)=16

3x+2y=k-2 =14

k=8

x=-2

y=10

4

x+y=2a

x-y=2b

x=a+b

y=a-b

6

a=-4

b=-5

c=-2

7

x=2

y=-2

a=1

b=-3

(a+b)^3=-8