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
Problem 1
subtract 3 x
5y=-3x+11
divide 5
y=3/5x+2.2'
Problem 2
add 5x
7y=5x+9
divide 7
y=5/7x+1.3'
'notice'
you can put 2.2 into a fraction (11/5) and 1.3 (9/7) if your teacher allows it, but i put them into decimals
Answer:
top left corner
Step-by-step explanation:
Answer:
Math is considered to be a part in everyones life, for example, you use math to throw a ball, like the force you use, or the height of the ball. Math is an important concept, and is lingering in our everyday lives, but the reason we take math is to find out of its exsitence, and use it for engineering, etc.
Step-by-step explanation:
<h3>
Answer: Choice A</h3>
0.10d + 0.05n = 2.25
d = 2n
================================================
Explanation:
n = number of nickels
d = number of dimes
we have twice as many dimes as nickels, so we could have something like 18 dimes and 9 nickels. Algebraically we would write d = 18 and n = 9. The equation that fits this is d = 2n. The answer is between A and B at this point.
We rule out choice B since the 0.05d is incorrect. It should be 0.10d to represent the total value of all the dimes.
Choice A is correct
d = number of dimes
0.10d = value of all the dimes in dollars
n = number of nickels
0.05n = value of all the nickels in dollars
0.10d + 0.05n = total value from both coins combined
2.25 = total value from both coins combined
0.10d + 0.05n = 2.25
