Which system of equations has only one solution?
a) 4x + 2y =8
-4x - 2y =3

b) -5x + y =6
5x - y = - 6

c) -3x + 4y = 2
3x - 4y =0

d) 2x + 4y = 6
3x - 4y =9

  D) 2X + 4Y = 6

       3X - 4Y =9

Step-by-step explanation:

Adding the equations can be informative. The sums are ...

  A) 0 = 11 . . . . . no solution

  B) 0 = 0 . . . . . infinite solutions

  C) 0 = 2 . . . . . no solution

  D) 5X = 15 . . . one solution (x, y) = (3, 0)

definitely a. the others have almost all data points on one side of the line.

step-by-step explanation:

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb