Question

2x+3y=9
3x+4y=5
Solve it by substitution method

Answer 1

2x+3y=9

3y=9-2x

y=(9-2x)/3

substitute in 3x+4y=5

3x+4(9-2x)/3 = 5

9x + 36 -8x =15

x + 36 =15

x= -21

y=(9-2x)/3

y = 3 - 2x/3

y = 3 - 2×(-21) /3

y=3+ 14

y=17

Answer 2

Answer:

x=-21 and y=17

Step-by-step explanation:

2x+3y=9 ............(i)

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

substitute equation (i) into (ii)

2x+3y=9,

2x=9-3y

x=9-3y/2........(iii)

3(9-3y/2)+4y=5

27-9y/2 +4y/1

27-9y/2+ 4y/1=27-9y +8y/2

27-y/2=5

27-y=10

-y=-17

y=17

from .......(iii)

x=9-3y/2

but y=17, so

x=9-3x17/2

x=9-51/2

x=-42/2=-21

x= -21

ans, y=17 and x=-21