solve using cross-multiplication :
(it will be good if u use the '2312' formula,then I will give brainliest)
4x + 6y = 15
3x - 4y = 7
Answers
Answer:
are partner sharing profit and lossees in the ration of 5:3:2 they admit A into partnership and give him 1/5th share of profits . Find the new profit -sharing ra
Answer:
Given equations are 4x+6y=15 and 3x−4y=7
By cross multiplication method, we know that, for a system of linear equations in x and y, of the form a
1
x+b
1
y+c
1
=0 and a
2
x+b
2
y+c
2
=0, we have:
b
1
c
2
−b
2
c
1
x
=
c
1
a
2
−c
2
a
1
y
=
a
1
b
2
−a
2
b
1
1
∴ x=
a
1
b
2
−a
2
b
1
b
1
c
2
−b
2
c
1
and y=
a
1
b
2
−a
2
b
1
c
1
a
2
−c
2
a
1
On comparing with a
1
x+b
1
y+c
1
=0 and a
2
x+b
2
y+c
2
=0 we have,
a
1
=4,b
1
=6,c
1
=−15 and a
2
=3,b
2
=−4,c
2
=−7
∴ x=
a
1
b
2
−a
2
b
1
b
1
c
2
−b
2
c
1
and y=
a
1
b
2
−a
2
b
1
c
1
a
2
−c
2
a
1
⇒x=
4×(−4)−3×6
6×(−7)−(−4)×(−15)
and y=
4×(−4)−3×6
−15×3−(−7)×4
⇒x=
−16−18
−42−60
and y=
−16−18
−45+28
⇒x=
−34
−102
and y=
−34
−17
⇒x=3 and y=
2
1
This is the required solution of the given system of equations using the cross multiplication method.