Question

2) 4x+y=11, 7x- 2y = 8
(Substitution method)​

Answer 1

Step-by-step explanation:

x=2

y=3

eq 1 4x+y=11

y=11-4x

substituting this value in eq 2

that is eq2 7x-2y=8

7x-2(11-4x)=8

7x-22+8x=8

15x=30

x=2

substituting this value of x in equation no. 1

4(2)+y=11

y=11-8

y=3

Answer 2

Solution:-

We have

$\rm \: 4x + y = 11 \: \: \: \: \: \: \: \: ...(i)$

$\rm \: 7x - 2y = 8 \: \: \: \: \: \: \: \: \: \: ....(ii)$

Now take (i) eq

$\rm \: 4x + y = 11$

$\rm \: y = 11 - 4x\: \: \: \: \: \: \: \: \: ....(iii)$

Now substitute (iii) eq on (ii) eq

$\rm \: 7x - 2y = 8 \: \: \: \: \: \: \: \: ...(ii)$

$\rm \: 7x - 2(11 - 4x) = 8$

$\rm \: 7x - 22 + 8x = 8$

$\rm \: 15x = 22 + 8$

$\rm15x = 30$

$\rm \: x = \dfrac{30}{15}$

$\boxed{ \rm \: x \: = 2}$

Now substitute the value of x on (iii) eq

$\rm \: y = 11 - 4x\: \: \: \: \: \: \: \: \: ....(iii)$

$\rm y = 11 - 4 \times 2$

$\rm \: y = 11 - 8$

$\boxed{ \rm \: y \: = 3}$