Question

Solve the system. x + y = 8 2x2 – y = –5 Add the equations, then choose the result. 3x2 = –13 3x2 = 3 2x2 + x = 3 2x2 = –13

Answer 1

2x^2 - y = -5
x + y = 8
----------------add
2x^2 + x = 3 <==

** 2x^2 and x cannot be added because they are not like terms

Answer 2

Option 3rd is correct

`2x^2+x=3`

Explanation:

Solve the system of equation:

`x+y = 8` ....[1]

`2x^2-y = -5` ....[2]

we can write equation [2] as :

`y= 2x^2+5`

Substitute the value of y in [1] we have;

`x+2x^2+5 = 8`

Subtract 5 from both sides we have;

`x+2x^2=3`

or

`2x^2+x=3`

Therefore, the result we get,
`2x^2+x=3`