Question

solve by substitution method root 2x +root 3y=0 and root 3x–root 8y=0

Answer 1

Solve the following pair of linear equations by the substitution method.
(i) x + y = 14 ; x – y = 4 (ii) s – t = 3 ; s/3 + t/2 = 6
(iii) 3x – y = 3 ; 9x – 3y = 9 (iv) 0.2x + 0.3y = 1.3 ; 0.4x + 0.5y = 2.3
(v)√2 x+ √3y = 0 ; √3 x - √8y = 0 (vi)3/2 x - 5/3y = -2 ; x/3 + y/2 = 13/6
(i) x + y = 14 ; x – y = 4
solve first equation
x + y = 14
x = 14 - y …………..(1)
plug this value in equation second we get
x – y = 4
14 – y - y = 4
Add 14 both side we get
- 2 y = 4 - 14
- 2 y = - 10
y = -10/-2
y = 5
Plug y = 5 in equation first we get
x = 14 – y
x = 14 – 5
x = 9
Answer x = 9 , y = 5
(ii) s – t = 3 ; s/3 + t/2 = 6

Solve first equation
s – t = 3
s = 3+t …………(1)
Plug this value in equation second we get
s/3 + t/2 = 6

Multiply by 6 to remove all denominator we get
6 + 2t + 3t = 36
5t = 36 – 6
5t = 30
Divide by 2 we get
t = 30/5
t =6
Plug the value in equation first we get
s = 3 +6
s = 9
Answer s = 9 , t = 6
(iii) 3x – y = 3 ; 9x – 3y = 9
solve first equation
3x – y = 3
3x =3 +y
x = (3 + y)/3 …………..(1)
Plug this value in equation second we get


9 is always equal to 9
So it is a true condition and in such condition

Answer 2

Hope it will help you....

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