Question

1.2x+2.8y = 4 and 2.8x+1.2y=4​

Answer 1

Answer:

1.2x+2.8y=4

multiply b. s by 10

12x+28y=40.....(1)

2.8x+1.2y=4

multiply b. s by 10

28x+12y=40....(2)

add (1)+(2)

12x+28y=40

+28x+12y=40

-------------------

40x+40y=80

x+y=2...(3)

sub(1)-(2)

12x+28y=40-(28x+12y=40)

12x+28y=40-28x-12y=-40

-16x+16y=0

-x+y=0....(4)

add (3)+(4)

x+y=2

-x+y=0

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2y=2

y=1

put y=1 in eqn (3)

x+y=2

x+1=2

x=1

(x, y) =(1,1)

Answer 2

Answer:

1.2X+2.8Y=4...(1)

2.8X+1.2Y=4...(2)

Multiply (1) by 2.8 and (2) by 1.2

3.36X+7.84Y=11.2...(1)

3.36X+1.44Y=4.8...(2)

Subtract (1) from(2) we get

(7.84-1.44)Y=11.2-4.8=>6.4Y=6.4=>

Y=6.4/6.4=1. Substitute Y=1 in equation(1) =>1.2X+2.8(1)=1 =>1.2X=4-2.8=1.2 =>X=1. Hence the solution for this system of linear equations given above is X=1 and Y=1.

Explanation:

It is the Commutative property of multiplication

Cuz, we are rearranging the numbers ig..

Im so sorry again if I am wrong..

I was never sure abt any of my answers.