solve each of the following systems, if possible. indicate whether the system has a unique solution, infinitely many solutions, or no solution.

a. 2x + 10y = 9
3x + 15y = 13

b. 2x + 8y = 5
3x + 12y = 7.5

c. y = 3-x

d. 5x -8y = -1
-5/2 x + 4y = 1/2​

Respuesta :

Answer:

(a) No solution

(b) Infinitely many solution

(c) No solution

(d) Infinitely many solution

Step-by-step explanation:

Solving (a):

[tex]2x + 10y = 9[/tex] --- (1)

[tex]3x + 15y = 13[/tex] --- (2)

Multiply (1) by 1.5

1.5 * [[tex]2x + 10y = 9[/tex]]

[tex]3x + 15y = 13.5[/tex] --- (3)

Subtract 2 and 3

[tex]3x - 3x + 15y - 15y = 13.5 - 13[/tex]

[tex]0 = 0.5[/tex]

The above is false; Hence, the system has no solution

Solving (b):

[tex]2x + 8y = 5[/tex] --- (1)

[tex]3x + 12y = 7.5[/tex] -- (2)

Multiply 1 by 1.5

1.5 * [[tex]2x + 8y = 5[/tex]]

[tex]3x + 12y = 7.5[/tex]

Subtract 2 and 3

[tex]3x - 3x + 12y - 12y = 7.5 - 7.5[/tex]

[tex]0 = 0[/tex]

The above implies that the system has infinitely many solutions

Solving (c):

[tex]y = 3 - x[/tex]

A second equation is required to solve for (c)

Solving (d):

[tex]5x - 8y = -1[/tex] --- (1)

[tex]-\frac{5}{2}x+ 4y = \frac{1}{2}[/tex] --- (2)

Multiply (2) by 2

[tex]-5x + 8y = 1[/tex] --- (3)

Add 1 and 3

[tex]5x - 5x -8y + 8y = -1 + 1[/tex]

[tex]0 = 0[/tex]

The above implies that the system has infinitely many solutions