Question

0.3x-0.2y=4
0.5x+0.3y= -7/17

Answer 1

where the heck are my medals?
lol.

Answer 2

Jk.

Answer 3

x = 100/17

y = -190/17

Answer 4

that answer is wrong

Answer 5

i used my Calculator man..
it cant be wrong.

Answer 6

it is wrong

Answer 7

If you rationalize the coefficients, then you obtain exact solutions. @saifoo.khan's solutions are correct.\[\left\{x\to \frac{100}{17},y\to -\frac{190}{17}\right\}= \{x\to 5.88235,y\to -11.1765\} \]

Answer 8

0,3x-0,2y=4 - after you multiplied every two equation with 10 you get
0,5x+0,3y=-7/17

3x-2y=40 ---- y=(40-3x)/(-2)
5x-3y=-70/17 ----- 85x-51y=-70 --- 85x-51(-40+3x)/2 =-70 -------
85x+(2040-153x)/2 =-70 ---- 170x +2040 -153x=-140 -----
17x=-2180 ----- x=(-2180)/17
- than x=-2180/17 --- y=(40-3(-2180/17))/(-2)
y=(680+6540)/(-34)
y=7220/(-34)=(-3610)/17

x=(-2180)/17
y=(-3610)/17

Answer 9

@jhonyy9,

You made an error in line four of your solution. For some reason you changed the sign of "+0,3y" to "-0,3y" Compare line 4 to line 2.

Your solutions for x and y will not verify when plugged into the second equation of the problem statement.

Answer 10

thank you @robtobey - yes -sorry

Answer 11

You had me going for a while.