Question

Resolver la siguiente ecuación por eliminación o sustitución: a-8b= -9 a-2b= -7

Answer 1

Answer: Solution:
`a=(-19)/(3)` and
`b=(1)/(3)` .

Explanation:

The given pair of equations:

`a-8b= -9\ ...(i)\\\\ a-2b= -7\ ...(ii)`

Eliminate equation (i) from (ii) , we get

`-2b-(-8b)=-7-(-9)\\\\\Rightarrow\ -2b+8b=-7+9\\\\\Rightarrow\ 6b=2\\\\\Rightarrow\ b=(1)/(3)`

Put value of b in (ii) , we get

`a-2*(1)/(3)=-7\\\\\Rightarrow\ a=-7+(2)/(3)\\\\\Rightarrow\ a=(-21+2)/(3)\\\\\Rightarrow\ a=(-19)/(3)`

Solution:
`a=(-19)/(3)` and
`b=(1)/(3)` .