chris65
slove equations and put it into a matrices
4t-5r=21
3t-7r=18
Delete
Share
This Question is Closed
lilg132
Best Response
You've already chosen the best response.
1
4t - 5r = 21 (multiply all by 7)
3t - 7r = 18 (multiply all by -5)
28t - 35r = 147
-15t + 35r = 90
add the two equations together
13t =237
t = 18.230769230769230769230769230769
4(18.230769230769230769230769230769) - 5r = 21
72.923076923076923076923076923077 - 5r = 21
72.923076923076923076923076923077 - 21 = 5r
51.923076923076923076923076923077 = 5r
10.384615384615384615384615384615 = r
not sure if this is right
chris65
Best Response
You've already chosen the best response.
1
i got the answer of t=57/13
and r=-9/13
but i have to put it into a matrices
lilg132
Best Response
You've already chosen the best response.
1
lol damn i had it right the first time
lilg132
Best Response
You've already chosen the best response.
1
let me write it out again
chris65
Best Response
You've already chosen the best response.
1
ok but i dont know how to put it into a matrix
lilg132
Best Response
You've already chosen the best response.
1
4t - 5r = 21
3t - 7r = 18
4t = 21 + 5r
divide everything by 4
t = 5.25 + 1.25r
3(5.25 + 1.25r) - 7r = 18
15.75 + 3.75r - 7r = 18
15.75 - 18 = 7r - 3.75r
-2.25 = 3.25r
-2.25 / 3.25 = 3.25r / 3.25
-9/13 = r
4t - 5(-9/13) = 21
4t + 45/13 = 21
4t = 21 - 45/13
4t = 228/13
4t / 4 = (228/13)/4
t = 57/13
lilg132
Best Response
You've already chosen the best response.
1
ok let me work out how to put into matrix
chris65
Best Response
You've already chosen the best response.
1
ok i got all that i just dont no how to make a matrix out of that
lilg132
Best Response
You've already chosen the best response.
1
no idea with matrixes going to have to ask someone else sorry
lilg132
Best Response
You've already chosen the best response.
1
im out of here bye
AriPotta
Best Response
You've already chosen the best response.
0
|dw:1354243922660:dw|
chris65
Best Response
You've already chosen the best response.
1
|dw:1354244060647:dw|
chris65
Best Response
You've already chosen the best response.
1
thats what i have to put my answer in
AriPotta
Best Response
You've already chosen the best response.
0
only two sets of brackets?
chris65
Best Response
You've already chosen the best response.
1
yes
AriPotta
Best Response
You've already chosen the best response.
0
are they only looking for Dt and Dr?
chris65
Best Response
You've already chosen the best response.
1
yes
AriPotta
Best Response
You've already chosen the best response.
0
|dw:1354244183257:dw|
there. lol
chris65
Best Response
You've already chosen the best response.
1
lol
chris65
Best Response
You've already chosen the best response.
1
ok i got another problem for ya
AriPotta
Best Response
You've already chosen the best response.
0
mer.
chris65
Best Response
You've already chosen the best response.
1
3x-z=4
x+y+7z=0
3x+y-z=4
and x=148/119
y=16/17
z=1
chris65
Best Response
You've already chosen the best response.
1
that also has to be into a matrices
AriPotta
Best Response
You've already chosen the best response.
0
oh. idk about 3 variable ones. i'm sorry :/
chris65
Best Response
You've already chosen the best response.
1
ok thanks