Question 65600This question is from textbook An Incremental Development
: Solve
1/4x - 1/5y = 2
0.03x - 0.4y = -1.64
This question is from textbook An Incremental Development
Answer by ptaylor(2198)   (Show Source):
You can put this solution on YOUR website! Solve
(1) 1/4x - 1/5y = 2
(2) 0.03x - 0.4y = -1.64
First, we'll convert (1) from fractions to decimals:
(1a) 0.25x - 0.2y = 2
(2) 0.03x - 0.4y = -1.64
Now we could multiply every term in both equations by 100. That would get rid of the decimals but we really don't need to do that to solve the problem:
Next, multiply (1a) by 2 and we get:
(1b) 0.50x - 0.4y = 4
(2) 0.03x - 0.4y = -1.64
Now, subtract (2) from (1b) and we have
0.47x =5.64
x=12
Substitute x=12 in (1a) above:
(1) 0.25(12) - 0.2y = 2 simplifying, we have
3-0.2y=2 subtract 3 from both sides
-0.2y=2-3
-0.2y=-1
y=5
CK
Now substitute x=12 and y=5 in (1) above
(1/4)(12)-(1/5)(5)=2
3-1=2
2=2
Substitute in (2)
0.03(12) - 0.4(5) = -1.64
.36-2=-1.64
-1.64=-1.64
Hope this helps------ptaylor
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