Question

Solve each given equation and show your work. tell whether it has one solution, an infinite number of solutions, or no solutions, and identify each equation as an identity, a contradiction or neither.

20-4x=12-x+8-3x

5x+4x-3= 24+8x

5x+6=2x+6+3x-15

Answer 1

(A) Subtracting the right side from both sides, we get ...

... (20 -4x) -(12 -x +8 -3x) = 0

... (20 -12 -8) +x(-4 +1 +3) = 0

... 0 = 0 . . . . . true for all values of x (infinite solutions)

(B) Subtracting the right side from both sides, we get ...

... (5x +4x -3) -(24 +8x) = 0

... x(5 +4 -8) +(-3 -24) = 0

... x -27 = 0

... x = 27 . . . . . . (one solution)

(C) Subtracting the right side from both sides, we get ...

... (5x +6) -(2x +6 +3x -15) = 0

... x(5 -2 -3) +(6 -6 +15) = 0

... 15 = 0 . . . . . . . not true for any value of x (no solutions)