Question

0.4x +0.3y =1.7 and 0.7x -0.2 = 0.8

Answer 1

here is your answer by Sujeet,

0.4x+0.3y=1.7 *0.7
o.7x-0.2y=0.8*0.4


By elimination method for solving the equation,

0.28x+0.21y=1.19
0.28x-0.8y=0.32

______________
0.29y=0.87
y=0.87/0.29
y=3


Now putting the value of y in another equation,
0.7x-0.2y=0.8
0.7x-0.2*3=0.8
0.7x-0.6=0.8
0.7x=0.8+0.6
0.7x=0.14
x=0.14/0.7
x=2


value of x =2
y=3



that's all




by SmArTY SUjeET

Answer 2

by using elimination method ,
(0.4x+0.3y=1.7)×2 -(1)
(0.7x+0.2y=0.8)×3 -(2)
subtract eqn (2) by (1),
1.4x+ 0.6y-0.8x-0.6y= 2.4-3.4
0.6x= -1.0
x=-10/6
now put the value in any original eqn,we get the value of y,
0.4×(-10/6)+0.3y=1.7
0.3y=17/10 +4/6
y=(17/10+2/3) / 0.3=? find your self