Answer:
B
I hope this could help you ^^
the error is that they didnt add the exponets
How do you solve this system of equations using the addition method:
4
x
−
y
=
−
4
;
5
x
+
2
y
=
−
18
?
Algebra
1 Answer
IDKwhatName
Jun 30, 2017
x
=
−
2
,
y
=
−
4
Explanation:
Right now, you have:
4
x
−
y
=
−
4
5
x
+
2
y
=
−
18
To make this easier, you must get rid of one variable, in this case I will remove
y
, to do this you must make the y-values in both equations the same.
To do this, I will multiply the whole of
4
x
−
y
=
−
4
by 2 to give
8
x
−
2
y
=
−
8
We now have:
8
x
−
2
y
=
−
8
5
z
+
2
y
=
−
18
All we need to do now is
(
8
x
−
2
y
+
5
x
+
2
y
)
=
(
−
18
−
8
)
≡
13
x
=
−
26
.
Divide both sides by 13 to find
x
:
13
x
=
−
26
13
x
13
=
−
26
13
x
=
−
2
Now put your value for
x
into either equation:
4
(
−
2
)
−
y
=
−
4
−
8
−
y
=
−
4
y
=
−
8
+
4
y
=
−
4
x
=
−
2
;
y
=
−
4
Answer link
Answer:
C. y = 2x + 8
Step-by-step explanation:
✔️First, find the slope of the line that goes through points (-2, 4) and (6, 20):
Slope (m) = ∆y/∆x = (20 - 4) / (6 - (-2))
Slope (m) = 16/8
m = 2
✔️Find the y-intercept (b):
To do this, substitute (x, y) = (6, 20) and m = 2 into y = mx + b
Thus:
20 = 2(6) + b
20 = 12 + b
20 - 12 = b
8 = b
b = 8
✔️Write the equation by substituting m = 2 and b = 8 into y = mx + b
Thus:
y = 2x + 8
