Question

Solve the system of equations x – 2y = 0, 3x + 4y = 20.

Answer 1

Given: x – 2y = 0, 3x + 4y = 20

Step-wise calculation:

Step 1: From x – 2y = 0, get x = 2y.

Step 2: Substitute into 3x + 4y = 20:

3(2y) + 4y = 20

⇒ 6y + 4y = 20

⇒ 10y = 20

⇒ y = 2

Step 3: Back-substitute:

x = 2y 

= 2 × 2 

= 4

The solution is x = 4, y = 2.