Question

como se resuelve 2x+3y=7 , 5x-y=9 con metodo de igualacion ?

Answer 1

2X + 3Y = 7 (1)

5X - Y = 9 (2)

En (1): 2X = 7 - 3Y:  X = 7/2 - 3Y/2

En (2): 5X = Y + 9: X = Y/5 + 9/5

X = X:   7/2 - 3Y/2 = Y/5 + 9/5

7/2 - 9/5 = Y/5 + 3Y/2

7/2 - 9/5 = [5(7) - 2(9)]/10 = [35 - 18]/10 = 17/10

Y/5 + 3Y/2 = [2(Y) + 5(3Y)]/10 = [2Y + 15Y]/10 = 17Y/10

17Y/10 = 17/10

Y = 1

Reemplazo Y = 1 en  X = 7/2 - 3Y/2

X = 7/2 - 3(1)/2

X = 7/2 - 3/2

X = 4/2

X = 2

Rta: X = 2, Y = 1  

Answer 2

Respuesta:

$2 \times + y = 5 \\ \\ \times - 3y = 2$