Question

0.4x + 0.3y=1.7
0.7x + 0.2y = 0.8
please answer​

Answer 1

Step-by-step explanation:

the answer will be

multipy in eqn 1 by2

and 2 by 3

u get ,

0.8x+0.6y=3.4

2.1x+0.6y=2.4

1.3x=5.8

x=5.8/1.3

x=58/13

put the value in eqn 1 u get urs answer perfectly

Answer 2

Answer:

x = -10/13 y=221/39

Step-by-step explanation:

0.4x +0.3y=1.7

4x/10 +3y/10=17/10

(4x +3y)/10=17/10

multiply both sides by 10

4x +3y=17 --------(i))

similarly, 0.7x +0.2y=0.8

7x +2y=8 --------(ii)

2y=8 -7x

y=(8-7x)/2

put y=(8-7x)/2

4x +3{(8-7x)/2}=17

4x +(24-21x)/2=17

(8x +24-21x)/2=17

8x +24-21x=17×2

8x -21x=34-24

-13x=10

x=-10/13

put x=-10/13 in (i)

4(-10/13)+3y=17

-40/13+3y=17

3y=17+40/13

3y=221/13

y=221/39