ALGEBRA - 4

Solve by substitution method

2x + y=11  and

x + y=10

solution

2x + y=11 ……….. (i)

x + y=10  …………..(ii)

from equation (ii)

x + y=10

x= 10-y  ………….(iii)

substitute (iii) in (i) above.

 2x + y=11

2(10-y) + y=11

20-2y+y = 11

20-y=11

20-11=y

y=9

From equation (iii)

x= 10-y 

x= 10-9

x=1

Hence y=9 and x=1