Question

3х + 4 = 12 ; y= 2х + 3
simultaneous equation​

Answer 1

Given :-

• Two equations :- 3х + 4 = 12 and y = 2х + 3

To Find :-

• The value of "x" and "y".

Solution :-

★ 1st equation

$~~~~~$ $\hookrightarrow {\sf {3x + 4 = 12}}$

$~~~~~$ $\hookrightarrow {\sf {3x = 12 - 4}}$

$~~~~~$ $\hookrightarrow {\sf {3x = 8}}$

$~~~~~$ $\hookrightarrow {\underline {\boxed {\sf {x = {\dfrac {8}{3}}}}}}$

★ 2nd equation

$~~~~~$ $\hookrightarrow {\sf {y = 2x + 3}}$

Now, substitute the value of "x" in 2nd equation.

$~~~~~$ $\hookrightarrow {\sf {y = 2 \times {\dfrac {8}{3}} + 3}}$

$~~~~~$ $\hookrightarrow {\sf {y = {\dfrac {16}{3}} + 3}}$

$~~~~~$ $\hookrightarrow {\sf {y = {\dfrac {16 + 3 \times 3}{3}}}}$

$~~~~~$ $\hookrightarrow {\sf {y = {\dfrac {16 + 9}{3}}}}$

$~~~~~$ $\hookrightarrow {\underline {\boxed {\sf {y = {\dfrac {25}{3}}}}}}$

Hence,

• ${\sf {The~ value~ of~ "x" = {\dfrac {8}{3}}}}$

• ${\sf {The~ value~ of~ "y" = {\dfrac {25}{3}}}}$

$~~~~~$$~~~~~$ $~~~~~$ V E R I F I C A T I O N

To verify our answer, let's substitute the value of "x" in 1st equation.

$~~~~~$ $\rightarrowtail {\sf {3x + 4 = 12}}$

$~~~~~$ $\rightarrowtail {\sf {{\cancel{3}} \times {\dfrac {8}{{\cancel{3}}}} + 4 = 12}}$

$~~~~~$ $\rightarrowtail {\sf {8 + 4 = 12}}$

$~~~~~$ $\rightarrowtail {\sf {12 = 12}}$

$~~~~~$ L.H.S. = R.H.S.

★ Hence, verified! ✔

Answer 2

Answer:

3x + 4 = 12

3x = 12 - 4

3x = 8

x = 8/3

now, put the value in eq. 2

2x + 3

2*8/3 + 3

16/3 + 3

now, take the L.C.M.

16 + 9/3

add 16 + 9 = 25/3

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