Question

2X+9Y =−38
X −9Y =35 Hallar X+Y

Answer 1

3x=-3
x=-1

-2+9y=-38
9y=-36
y=-4

x+y=-1-4=-5

Answer 2

2x + 9y = −38
x − 9y = 35 

x =  −38 − 9y/2
x  = 35 + 9y

−38 − 9y/2 =  35 + 9y
−38 − 9y  = 2(35 + 9y)
−38 − 9y =  70 + 18y
− 9y − 18y = 70 + 38
− 27y = 108
y = 108/− 27
y = − 4

x − 9y = 35 
x − (−36) = 35
x + 36 = 35
x = − 1

Respuestas:
x = − 1
y = − 4

Y Hallar x+y
x + y
− 1 + (− 4)
− 1− 4 = − 5