Mathematics
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OpenStudy (anonymous):
I have to solve the system of equations in this problem (which i have noooo idea what that means XD)
2x + 3y = 1
y = 3x = 15
help??
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jimthompson5910 (jim_thompson5910):
there seems to be a typo in "y = 3x = 15"
OpenStudy (anonymous):
Oh! Its supposed to be y = 3x + 15 oops XD
jimthompson5910 (jim_thompson5910):
start with the first equation 2x + 3y = 1
and replace every y with 3x+15 (since y = 3x+15)
jimthompson5910 (jim_thompson5910):
doing that gives you
2x + 3y = 1
2x + 3(3x+15) = 1
solve for x from here
OpenStudy (anonymous):
oh!
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OpenStudy (anonymous):
Wow thanks @jim_thompson5910
jimthompson5910 (jim_thompson5910):
you're welcome
jimthompson5910 (jim_thompson5910):
and once you get the value of x, you use y = 3x+15 to find y
OpenStudy (anonymous):
ok cool
OpenStudy (anonymous):
so @jim_thompson5910 the correct answer for x is -1?
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jimthompson5910 (jim_thompson5910):
x = -1 is incorrect
OpenStudy (anonymous):
Oh really?
OpenStudy (anonymous):
I did
2x + 3(3x + 15) = 1
2x + 9x + 45 = 1
11x + 45 = 1
11x = -44
x = -1
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
11x = -44 does not lead to x = -1
OpenStudy (anonymous):
OOOH! its -4 ? @jim_thompson5910
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OpenStudy (anonymous):
oops XD
jimthompson5910 (jim_thompson5910):
yep, x = -4
jimthompson5910 (jim_thompson5910):
and y = ??
OpenStudy (anonymous):
y = 2?
OpenStudy (anonymous):
@jim_thompson5910
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jimthompson5910 (jim_thompson5910):
y = 3x + 15
y = 3(-4) + 15 .... replace x with -4
y = -12 + 15
y = 3
jimthompson5910 (jim_thompson5910):
you were close
OpenStudy (anonymous):
oh i just added wrong XD thsnkyou!!
jimthompson5910 (jim_thompson5910):
you're welcome