This is Linear Algebra Solve each system below Express each
This is Linear Algebra.
Solve each system below. Express each solution in vector form.
a)
x1+x2-x3-x4 = 3
4x1+x2 =5
x2-x3-x4=2
b)
4/x - 3/y = 10
3/x + 2/y = 1
c)
x1+ x2 = 5
2x1 + x2 =6
3x1 + x2 = 7
Solution
a) Given equations are:
x1+x2-x3-x4=3 -----------(1)
4x1+x2 =5 -----------(2)
x2-x3-x4=2 -----------(3)
from from eq(3) : x2-x3-x4=2
substitute these two in eq(1):
x1+x2-x3-x4=3
x1+2=3
x1 = 1
from eq (2)
x2=5-4x1
x2=5-1
x2=1
and from eq (3) and x1=1,x2=1
x2 -x3-x4=2
-(x3+x4)=2-1 =1
x3+x4=-1
vector form (x1 5-4x1 -x4-1 x4)
b) 4/x-3/y=10
3/x+2/y =1
if take as (1/x)=a,(1/y)=b;
then 4a-3b=10
3a+2b=1
by solve this b=1-3a/2
4a-3(1-3a/2)=10
4a-3/2 +9a/2=10
17a/2=10+3/2 = 17a=23
a=23/17
then x=17/23
from this b=
3a+2b=1
3(23/17)+2b=1
2b=1-69/17
=-52/17
b=-26/17
then y=-17/26
vector form (17/23, -17/26)
c) x1+x2=5 ----(1)
2x1+x2=6 -----(2)
3x1+x2=7 ------(3)
add (2),(3)
5x1+2x2=13 ----(4)
now solve (1),(4)
eq (4) - eq (1 )*2
5x1+2x2=13
2x1+2x2=10
then 3x1=3
x1=1
from x1, x2=4
vector form (1,4)


