Question

3x +y = 23; 4x - 7y +11 = 0 by substitution method​

Answer 1

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Answer 2

Answer:

3x+y=23 ---(1)

4x-7y= -11 --(2)

--------------------------------‐-----------------------

4x=-11+7y

x= –11+7y --(3)

4

Then substitute equation no.(3) in (1)

3x+y=23

3[–11+7y]+y=23

4

-33+21y+y=23

4

-33+21y + y =23

4 1

-33+21y×1 + yx4=23

4×1 1x4

-33+21y + 4y=23

4 4

-33+21y+4y=23

4

-33+25y=23

4

-33+25y=23×4

-33+25y=92

25y=92+33

25y=125

y=125

25

y=5 --(4) [Subsitute this equation no.(4) in (3)]

x=–11+7y

4

x=-11+7×5

4

x=–11+35

4

x=24

4

x=6

Therefore y=5 and x=6.