Question

Find the value of x+y, if 2x+y=7 and
3x +2y = 12​

Answer 1

correct answer is( x=2 and y=2)

Answer 2

Answer

First we should find the value of x and y. The substitution method would be more easier.

$\sf \dashrightarrow 2x + y = 7 \: \: --- (i)$

$\sf \dashrightarrow 3x + 2y = 12 \: \: --- (ii)$

By equation i,

$\sf \dashrightarrow 2x + y = 7$

$\sf \dashrightarrow 2x = 7 - y$

$\sf \dashrightarrow x = \dfrac{7 - y}{2}$

Now, let's find the value of y by second equation.

$\sf \dashrightarrow 3x + 2y = 12$

$\sf \dashrightarrow 3 \bigg( \dfrac{7 - y}{2} \bigg) + 2y = 12$

$\sf \dashrightarrow \dfrac{21 - 3y}{2} + 2y = 12$

$\sf \dashrightarrow \dfrac{21 - 3y + 4y}{2} = 12$

$\sf \dashrightarrow \dfrac{21 + y}{2} = 12$

$\sf \dashrightarrow 21 + y = 12 \times 2$

$\sf \dashrightarrow 21 + y = 24$

$\sf \dashrightarrow y = 24 - 21$

$\sf \dashrightarrow y = 3$

Now, we can find the value of x by first equation.

$\sf \dashrightarrow 2x + y = 7$

$\sf \dashrightarrow 2x + 3 = 7$

$\sf \dashrightarrow 2x = 7 - 3$

$\sf \dashrightarrow 2x = 4$

$\sf \dashrightarrow x = \dfrac{4}{2}$

$\sf \dashrightarrow x = 2$

Now, we can find x + y by substituting the values of x and y

$\sf \dashrightarrow x + y$

$\sf \dashrightarrow 2 + 3$

$\sf \dashrightarrow 5$

Hence, the answer is 5.