Question

Arrange the steps fo solving given linear equations using substitution method from top to bottom.
x+y=15
2x-3y=6

• A. x = 15 - y
• B. x+y=15 & 2x-3y=6
• C. 2(15 - y) - 3y=5
• D. x +5=15, ⇒ x=10
  

Answer 1

x + y = 15 & 2x - 3y = 5

From equation x + y = 15
$⟹$x = 15 - y

Now, substitute the value of x in
2x - 3y = 5

$⟹$ 2(15 - y) - 3y = 5

$⟹$ 30 - 2y - 3y = 5

$⟹$ 30 - 5y = 5

$⟹$ 30 - 5 = 5y

$⟹$ 25 = 5y

$⟹$ y = $\frac{25}{5}$

$⟹$ y = 5

Substitute the value of y in x + y = 15

$⟹$ x + 5 = 15

$⟹$ x = 15 - 5

$⟹$ x = 10