Question

2x+y=8,x+2y=7 bý substitution​

Answer 1

Given:

• 2x + y = 8      ----- [Equation 1]
• x + 2y = 7      ----- [Equation 2]

To find:

The values of x and y

Solution:

Let us consider Equation 1.

2x + y = 8

➥ y = 8 - 2x     ----- [Equation 3]

Substitute the value of y from Equation 3 in Equation 2.

x + 2y = 7

↠ x + 2(8 - 2x) = 7

➟ x + 16 - 4x = 7

➝ 16 - 7 = 4x - x

➝ 9 = 3x

➝ x = 9 ÷ 3

∴ x = 3

Now, substitute the value of x in Equation 3 to find the value of y

y = 8 - 2x

→ y = 8 - 2(3)

➝ y = 8 - 6

∴ y = 2