Question

solve simultaneous linear equation by substitution x/4+3y=18 ; y-x/3=1​

Answer 1

Answer:

First equation :

x/4 + 3y = 18

Second equation :

y - x/3 = 1

Solving 1st:

x/4 + 3y = 18 =) x + 12y = 18 × 4

=) x + 12y = 72

=) x = 72 - 12y (eq.3)

Solving 2nd:

y - x/3 = 1 =) 3y - x = 3 (eq.4)

putting eq.3 in eq.4,

3y - (72 - 12y) = 3

15y - 72 = 3

15y = 75

y = 75/15 = 5

Now, using eq.3,

x = 72 - 12 × 5 = 72 - 60 = 12

Answer: x = 12, y = 5