SIMULTANEOUS EQUATIONS 2

Solve the following equations by substitution method.

   6x + y = 15

   x +  y = 5

solution

6x  + y = 15 ----------- (i)

x + y = 5 ---------- (ii)

from equation (i)

6x + y = 15

y = 15 - 6x ----------(iii)

Substitute equation (iii) in (ii) above,

x + (15 - 6x) = 5

x + 15 - 6x = 5

x - 6x = 5 - 15

-5x  = -10

-5x  = -10

-5       -5

x = 2

From equation (iii)

y = 15 - 6x ----------(iii)

y = 15 – 6(2)

y = 15 – 12

y = 3

Hence x=2 and y=3.

TRY THIS......................

Solve the following equations by substitution method.

     6x - 5y = 9

     x + 2y = 10