Question

2x+3y=9    3x+4y=5   system of equations by using the method of substitution.

Answer 1

x= -21 and y= 17 are the values obtained by solving given equations using substitution method.

Given:  2x +3y = 9 _______(1),

           3x + 4y = 5 ______(2)

From (1)  2x = 9 – 3y

          x=$\frac{9-3 y}{2}$  ______ (3)

Substitute (3) in (2)

$3\left(\frac{9-3 y}{2}\right)+4 y=5\\\\\left(\frac{27-9 y}{2}\right)+4 y=5$

27 – 9y + 8y = 10  

27 – 10 = y  

y = 17 ______(4)  

Substitute (4) in (1)

2x +3(17) = 9  

2x = 9 – 51  

2x = -42  

x = -21 and y = 17.  

Answer 2

Answer:

Step-by-step explanation:

Solution :-

Here, we have

the given equations are

⇒ 2x + 3y = 9 .... (i)

⇒ 3x + 4y = 5 ... (ii)

From equation (i), we get

⇒ 3y = 9 - 2x

⇒ y = 9 - 2x/3 ...... (iii)

Putting y's value in eq (ii), we get

⇒ 3x + 4 (9 - 2x/3) = 5

⇒ 9x + 36 - 8x/3 = 5

⇒ x + 36 = 15

⇒ x = 15 - 36

⇒ x = - 21

Putting x's value in eq (iii), we get

⇒ y = 9 - 2x/3

⇒ y = 9 - 2 × (- 21)/3

⇒ y = 9 + 42/3

⇒ y = 17

Here, x = - 21 and y = 17

Hence, the solution of the given equation is x = - 21, y = 17.