Question

solve this question by comparison method.

1. 0.4x+0.3y=1.7,
0.7x-0.2y=0.8

2. 0.3x+0.5y=0.5,
0.5x+0.7y=0.74
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Answer 1

Step-by-step explanation:

The values are mentioned in the picturr

Answer 2

Step-by-step explanation:

Given,

0.5x + 0.7y = 0.74

0.3x - 0.5y = 0.5

Now,

Multiply (1) and (2) by 100,

50x + 70y = 74

30x + 50y = 50

Now,

From (3) we have,

50x = 74 - 70y

x = (74 - 70y)/50

Here,

Putting value of x in (4),

30x + 50y = 50

30 (74 - 70y)/50 + 50y = 50

3(74 - 70y)/5 + 50y = 50

[(222 - 210y) + 250y]/5 = 50

[222 - 210y + 250y] = 50 × 5

40y = 250 - 222

40y = 28

y = 28/40

y = 7/10

y = 0.7

Now,

Substituting value of y in (5),

x = (74 - 70y)/50

x = (74 - 70 × 0.7)/50

x = (74 - 49)/50

x = 25/50

x = 5/10

x = 0.5

Therefore,

x = 0.5 and y = 0.7