Explanation

We are given two equations:

Let:

• Cost of one apple = x

• Cost of one orange = y

From the problem:

1. $4x + 2y = 30$
   

2. $$x+3y=15

   
   Step 1: Solve the system of equations

Equation (1):
$4x + 2y = 30$
Divide the whole equation by 2:
→ $2x + y = 15$→ (3)

Equation (2):
$x + 3y = 15$ → (2)

Step 2: Solve equations (2) and (3)

From (3):
$y = 15 - 2x$ → (4)

Substitute (4) into (2):
$x + 3(15 - 2x) = 15$
$x + 45 - 6x = 15$
$-5x+45=15$
$-5x=15-45=-30$
$$x=−30−5=6