Question

3x+2y=9
x+3y=12
Simultaneous equation​

Answer 1

Answer:

x = 4/7

y = 27/7

Step-by-step explanation:

GIVEN :-

• 3x + 2y = 9    ------ [Equation 1]
• x + 3y = 12     ------ [Equation 2]

Here, I have solved the equations using Substitution method. This can also be done using Elimination method or cross multiplication method.

Let us consider Equation 2.

x + 3y = 12

➥ x = 12 - 3y

Substitute the value of x in Equation 1

3x + 2y = 9

➝ 3(12 - 3y) + 2y = 9

➝ 36 - 9y + 2y = 9

➝ 36 - 7y = 9

➝ 7y = 9 - 36

➝ 7y = 27

➝ y = 27 / 7

Substitute the value of y in Equation 2 to find the value of x

x = 12 - 3y

$\Rightarrow \: \sf{x = 12 - 3 \bigg(\dfrac{27}{7}\bigg)}$

$\Rightarrow \: \sf{x =12 - \dfrac{81}{7}}$

$\Rightarrow \: \sf{x = \dfrac{84 - 81}{7}}$

$\therefore \: \boxed{\bf{x = \dfrac{4}{7}}}$