Question

solve for x and y and plz explain also .8x +.3y = 3.8 , .4x - 5y = 0.6.​

Answer 1

Step-by-step explanation:

.8x+.3y= 3.8.............(1)

.4x-.5y= 0.6................(2)

we know that: .8= 8/10, .3= 3/10, 3.8= 38/10, .4= 4/10, .5= 5/10, 0.6= 6/10

so, by removal of decimals, we have.........

8x/10+3y/10= 38/10...............(1)

4x/10 - 5y/10= 6/10..................(2)

by taking LCM: LCM= 10 in both equations

so, 8x+3y/10= 38/10.................(1)

4x-5y/10= 6/10..........................(2)

by cancelling 10 in denominators in both equations.....

so, 8x+3y= 38...................(1)

4x-5y= 6..................(2)

equation (2) multiply by 2

so, 2(4x-5y= 6).......(2)

8x-10y= 12................(2)

now, equation, (1)-(2)

we have,

8x+3y-(8x-10y)= 38-12

8x+3y-8x+10y= 26

by cancelling 8x in LHS side,

3y+10y= 26

13y= 26

y= 26/13= 2

so, y= 2

by substituting y value In equation (1)

so, 8x+3(2)= 38

8x+6= 38

8x= 32

x= 32/8=4

x=4

so, x=4, y=2