Advertisements
Advertisements
प्रश्न
Solve :
`[ 7 + x ]/5 - [ 2x - y ]/4 = 3y - 5`
`[5y - 7]/2 + [ 4x - 3 ]/6 = 18 - 5x`
Advertisements
उत्तर
`[ 7 + x ]/5 - [ 2x - y ]/4 = 3y - 5` .....(Given)
⇒ 4( 7 + x ) - 5( 2x - y ) = 20( 3y - 5 )
⇒ 28 + 4x - 10x + 5y = 60y - 100
⇒ - 6x - 55y = - 128 ......(1)
`[5y - 7]/2 + [ 4x - 3 ]/6 = 18 - 5x` ......(Given)
⇒ 3(5y - 7) + 4x - 3 = 6( 18 - 5x )
⇒ 15y - 21 + 4x - 3 = 108 - 30x
⇒ 34x + 15y = 132 .......(2)
Multiplying equation (1) by 34 and equation (2) by 6, We get
- 204x - 1870y = - 4352 .....(3)
204x + 90y = 792 ......(4)
Adding equation (3) and (4), We get
- 204x - 1870y = - 4352 .....(3)
+ 204x + 90y = 792
- 1780y = -3560
⇒ y = 2
Substituting y = 2 in equation (1), We get
- 6x - 55 x 2 = - 128
⇒ - 6x - 110 = - 128
⇒ - 6x = - 18
⇒ x = 3
∴ Solution is x = 3 and y = 2.
APPEARS IN
संबंधित प्रश्न
For solving pair of equation, in this exercise use the method of elimination by equating coefficients :
13 + 2y = 9x
3y = 7x
Solve the following simultaneous equation :
8v - 3u = 5uv
6v - 5u = -2uv
Solve the following simultaneous equations:
41x + 53y = 135
53x + 41y = 147
Solve the following pairs of equations:
`(3)/x - (1)/y` = -9
`(2)/x + (3)/y` = 5
Solve the following pairs of equations:
`(2)/(x + 1) - (1)/(y - 1) = (1)/(2)`
`(1)/(x + 1) + (2)/(y - 1) = (5)/(2)`
Solve the following pairs of equations:
`(5)/(x + y) - (2)/(x - y)` = -1
`(15)/(x + y) + (7)/(x - y)` = 10.
Solve the following pairs of equations:
`(2)/(3x + 2y) + (3)/(3x - 2y) = (17)/(5)`
`(5)/(3x + 2y) + (1)/(3x - 2y)` = 2
The length of a rectangle is twice its width. If its perimeter is 30 units, find its dimensions.
A person goes 8 km downstream in 40 minutes and returns in 1 hour. Determine the speed of the person in still water and the speed of the stream.
Salman and Kirti start at the same time from two places 28 km apart. If they walk in the same direction, Salman overtakes Kirti in 28 hours but if they walk in the opposite directions, they meet in 4 hours. Find their speeds (in km/h).
