How do solve the following linear system?: 4x+3y=1,−6x−2y=−8?

1 Answer
Shiva Prakash M V
Jun 6, 2018

the solution is:

(x,y)≡(2.2,−2.6)

Explanation:

4x+3y=1------(1)

−6x−2y=−8------(2)

If
a11x+a12y=b11
a21x+a22y=b21

Then,

x=b11a22−b21a12a11a22−a21a12

y=a11b21−a21b11a11a22−a21a12

Here,

a11=4;a12=3;b11=1

a21=−6;a22=−2;b21=−8

Substituting

x=1×(−2)−(−8)×34×(−2)−(−6)×3=−2+24−8+18=2210=2.2

y=4×(−8)−(−6)×14×(−2)−(−6)×3=−32+6−8+18=−2610=−2.6

Check:

lhs=4x+3y=4×2.2+3×(−2.6)=8.8−7.8=1=rhs

lhs=−6x−2y=−6×2.2−2×(−2.6)=−13.2+5.2=−8=rhs

Hence,
the solution is:

(x,y)≡(2.2,−2.6)

Related questions
See all questions in Systems Using Substitution
Impact of this question
1712 views around the world
You can reuse this answer
Creative Commons License