Solve the system of equations by substitution. What is the solution for x?
2x + y = 1
4x + 2y = −2
x = 0
x = 2
There is no x value, as there is no solution.
x can be any value, as there is an infinite number of solutions.
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TheSmartOne (thesmartone):
Ok, so which equation do you want to handle first? :)
TheSmartOne (thesmartone):
Also, welcome to OpenStudy! :D @casey321123 @~
OpenStudy (anonymous):
i am not really understanding how to do this problem
TheSmartOne (thesmartone):
ok, let's take the #1 equation :)
which is 2x + y = 1
TheSmartOne (thesmartone):
now let's solve for y in that equation :D
2x + y = 1
Subtract 2x on both sides, what do you get?
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OpenStudy (anonymous):
y=1-2x
TheSmartOne (thesmartone):
correct, now we plug that equation into the second equation
TheSmartOne (thesmartone):
4x + 2y = −2
so in place of y over there, we plut in 1-2x
so we get:
4x + 2(1-2x) = -2
solve for x :)
OpenStudy (anonymous):
x=-2
TheSmartOne (thesmartone):
4x + 2(1-2x) = -2
First use the distributive property
a(b-c) = ab - ac
so
2(1-2x) = ?
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TheSmartOne (thesmartone):
not sure how you got x = -2
TheSmartOne (thesmartone):
so let's do it step by step :)
OpenStudy (anonymous):
ok
TheSmartOne (thesmartone):
so what is 2(1-2x) = ?
OpenStudy (anonymous):
idk what to do
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TheSmartOne (thesmartone):
Use the distributive formula
a(b-c) = ab - ac
so
2(1-2x) = ??
What is 2 x 1 = ?
what is 2 x 2 = ?
OpenStudy (anonymous):
2 and 4
TheSmartOne (thesmartone):
ok, good
so 2(1-2x) = 2 - 4x
OpenStudy (anonymous):
ok
TheSmartOne (thesmartone):
4x + 2 - 4x = -2
What is 4x - 4x = ?
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OpenStudy (anonymous):
x
TheSmartOne (thesmartone):
nope
4x - 4x = (x)(4-4)
What is 4-4 =?
OpenStudy (anonymous):
0
TheSmartOne (thesmartone):
correct so 4x - 4x = (4-4)(x) = 0x = 0
OpenStudy (anonymous):
no solution
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TheSmartOne (thesmartone):
so tell me, @casey321123 does \(\sf -2 = 2\)?
TheSmartOne (thesmartone):
exactly! It's no solution! :D
TheSmartOne (thesmartone):
when we get no solution, that means, that the two lines are parallel. :)
Great job! :D