Advertisements
Advertisements
प्रश्न
If 10y = 7x - 4 and 12x + 18y = 1 ; find the value of 4x + 6y and 8y - x.
Advertisements
उत्तर
10y = 7x - 4 ........(1)
12x + 18y = 1 ........(2)
Multiplying (1) by 9 and (2) by 5, we get,
63x - 90y = 36 ........(3)
60x + 90y = 5 ........(4)
Adding (3) and (4), we get,
123x = 41
⇒ x = `(41)/(123) = (1)/(3)`
∴ 10y = `(7)/(3) - 4`
= `(7 - 12)/(3)`
= `(-5)/(3)`
⇒ y = `(-5)/(3) xx (1)/(10)`
= `(-1)/(6)`
∴ 4x + 6y = `(4)/(3) - 1`
= `(1)/(3)`
8y - x
= `(-8)/(6) - (1)/(3)`
= `(-8 - 2)/(6)`
= `(-10)/(6)`
= `(-5)/(3)`.
APPEARS IN
संबंधित प्रश्न
For solving pair of equation, in this exercise use the method of elimination by equating coefficients :
2x − 3y − 3 = 0
`[2x]/3 + 4y + 1/2` = 0
For solving pair of equation, in this exercise use the method of elimination by equating coefficients :
13x+ 11y = 70
11x + 13y = 74
10% of x + 20% of y = 24
3x - y = 20
Solve the following simultaneous equations:
103a + 51b = 617
97a + 49b = 583
If 2x + y = 23 and 4x - y = 19 : find the value of x - 3y and 5y - 2x.
`4x + 6/y = 15 and 6x - 8/y = 14.` Hence, find a if y = ax - 2.
If 1 is added to the denominator of a fraction, the fraction becomes `(1)/(2)`. If 1 is added to the numerator of the fraction, the fraction becomes 1. Find the fraction.
Anil and Sunita have incomes in the ratio 3 : 5. If they spend in the ratio 1 : 3, each saves T 5000. Find the income of each.
A boat goes 18 km upstream in 3 hours and 24 km downstream in 2 hours. Find the speed of the boat in still water and the speed of the stream.
A and B can build a wall in `6(2)/(3)` days. If A's one day work is `1(1)/(4)` of one day work of B, find in 4 how many days A and B alone can build the wall.
