Question

In the following equations, let x=−3 and y=2/3. Determine whether the following equations are true, false, or neither true nor false.

7. xy =−2
8. x+3y=−1
9. x+z=4
10. 9y=−2xx
11. y/x=−2

Answer 1

(7) True

(8) true

(9) Neither true nor false

(10) False

(11) False

Explanation:

We have given x = -3 and
`y=(2)/(3)`

We have to find that the expression given bellow is true or false

(7) xy= -2

So
`-3* (2)/(3)=-2`

Hence it is true

(8)
`x+3y=-1`

`-3+3* (2)/(3)=-3+2=-1`

Hence it is true

(9) x+z = 4

We have not given value of z so we can say that it is true or false

So it is neither true nor false

(10)
`9y=-2x^2`

So
`9* (2)/(3)=-2* (-3)^2`

`6=-18`

Hence it is not true

(11)
`(y)/(x)=-2`

`(y)/(x)=((2)/(3))/(-3)=(-2)/(9)`

Hence it is false