Question

realizar con el método de igualación                                                                            a) {10x+18y= -11
      {16x-9y= -5

Answer 1

10x+18y= -11--
16x -9y = -5-- ----
despejamos x  en ambos casos y luego igualamos--
10x = -11-18y--
X=(-11-18y)/10.......(1)----
16x = -5 +9y----
X=(-5+9y)/16.........(2)----
igualando----
(-11-18y) / 10 = (-5+9y) / 16----
16(-11 - 18y) = 10 (-5+9y)---
- 176 - 288y = -50 + 90y ---
-176 +50 = 90y + 288 y---
-126 = 378 y--
-126/378 = y--
-1/3 = y--
luego lo reemplazas el valor en cualquier ecuación---
10x + 18(-1/3) = -11--
10x + -6 = -11--
10x = -11 + 6--
10x = -5--
x = -5/10--
x = -1/2

Answer 2

Resolver por metodo de igualacion.

10x + 18y = -11 (1)
16x - 9y = -5 (2)
despejamos de (1) Y (2) x

10x +18y = - 11
10x = -11 -18y
x = (-11 - 18y) /10 (3)

16x -9y = -5
16x = - 5+9y
x = ( -5 + 9y)/16 (4)

Igualamos (3) y ( 4)
(- 11 -18y ) /10 = ( -5 +9y ) /16
16 ( - 11 -18y) = 10 ( -5 + 9y)
-176 - 288y = -50 +90y
- 176 +50 = 288y +90y
-126 = 378y
126/378 = y
-1/3 = y
y = -1/3

Reemplazamos el valor de y en (1)
10x +18y = -11
10x +18( -1/3) = -11
10x -6 = -11
10x = -11 +6
10x = -5
x =  - 5/10
x = -1/2

Solucion
x = - 1/2
y = - 1/3


comprobacion:
tomamos (1)
10x +18y = - 11
10( -1/2) + 18( -1/3) = - 11
-5 -6 = - 11
-11  = - 11