Question

find the value of R ,if x=3 y =-4 is a solution of equation Rx+4y=5 ​

Answer 1

Answer:

4/x + 5y = 7 ....(i)

3/x + 4y = 5....(ii)

Assume 1/x = u

4u + 5y =7...(iii)

3u + 4y = 5...(iv)

3 x Equation (iii) - 4 x equation (iv)

12u + 15 y - 12u - 16y = 21 - 20

y = -1

Put value of y in equation (iii)

4u = 7 + 5

u = 12/4 = 3

x = 1/3

Hence value of x, y are 1/3, -1 respectively.

Answer 2

Answer:

R = 7

Step-by-step explanation:

Rx+4y=5

Given:

x= 3

y= -4

put x & y in the equation

$r(3) + 4( - 4) = 5$

$3r + ( - 16) = 5 \\ 3r = 5 + 16 \\ 3r = 21 \\ r = \frac{21}{3} \\ r = 7$

Hence, R = 7