Solve the followi

Putting these value in given equations, we get

So, the given equations transforms into linear equation in two variables i.e.

15a + 4b = 42 … (i)

3a + 2b = 12 …..(ii)

Multiply equation (ii) by 5, so

15a + 4b = 42 … (iii)

15a + 10b = 60 …..(ii)

Subtract (iii) from (ii),

15a + 10b – 15a – 4b = 60 – 42

⇒ 6b = 18

⇒ b = 3

Putting above value in (ii),

3a + 2× 3 = 12

⇒ 3a = 12 – 6

⇒ 3a = 6

⇒ a = 2