x+y=-2 and 2x+4y=-14 by substitution method
Answers
Answer:
Explanation:
solving the first equation for
x
:
substracting
3
y
2
x
=
1
+
3
y
dividing by
2
we get
x
=
1
2
+
3
2
y
plugging this in the second equation
5
(
1
2
+
3
2
y
)
+
4
y
=
14
multiplying by
2
5
(
1
+
3
y
)
+
8
y
=
28
5
+
15
y
+
8
y
=
28
collecting like Terms
23
y
+
5
=
28
substracting
5
and dividing by
23
y
=
1
so we get
x
=
1
2
+
3
2
=
4
2
=
2
Answer is x=3 and y=-5
Step-by-step explanation:
Given:- x+y=-2
2x+4y=-14
To find:- Value of x and y
Formula used:- Using Substitution Method
The substitution method can be defined as a way to solve a linear system algebraically. The substitution method works by substituting one y-value with the other. To put it simply, the method involves finding the value of the x-variable in terms of the y-variable.
Solution:-
Consider the same equations as
x + y = -2
x= -2 - y ———–(i)
And,
2x + 4y = -14 ———–(ii)
Now putting value of x from equation (i) to equation (ii)
2x + 4y = -14
2*(-2-y) + 4y = -14
-4 - 2y + 4y= -14
-4 + 2y = -14
2y = -14 +4
2y= -10
y= -5
Now putting value of y in equation (i)
x = -2 -y
x= -2 - (-5)
x= -2 +5
x=3
So, x=3 and y=-5