Respuesta :
Answer:
(x,y)=(1,5)
Step-by-step explanation:
6x+3y=21/*2
-12x+y=-7
12x+6y=42 (1)
-12x+y=-7 (2)
(1)+(2): 7y=35
-12x+y=-7
y=35/7
-12x+y=-7
y=5
-12x+5=-7
y=5
-12x=-7-5
y=5
-12x=-12
y=5
x=-12/(-12
y=5
x=1
(x,y)=(1,5)
Answer:
x=1,y=5
Step-by-step explanation:
6x+3y=21....(1)
-12x+y=-7.....(2)
From (2) make y the subject of formula
y=-7+12x...(3)
Substitute (3) into (1)
6x+3(-7+12x)=21
6x-21+36x=21
Collect like terms
6x+36x=21+21
42x=42
Divide both sides by 42
x=1
Substitute the value of x into (3)
y=-7+12(1)
y=-7+12
y=5
Therefore x=1,y=5