Question

Evaluate 3xy- y + 6z when x = 1, y = - 2 and z = 3

Answer 1

14

Explanation:

`3xy- y + 6z \\\\x = 1\\ y = - 2 \\ z = 3\\\\3(1)(-2) - (-2) +6(3)\\-6 + 2 +18\\=14`

Answer 2

`\boxed{ \bold{ \huge{ \boxed{ \sf{14}}}}}`

Explanation:

Given, x = 1 , y = -2 , z = 3

`\sf{3xy - y + 6z}`

Plug the value of x , y and z

⇒
`\sf{3 * 1 * ( - 2) - ( - 2) + 6 * 3}`

Multiply the numbers

⇒
`\sf{ - 6 - ( - 2) + 6 * 3}`

We know that ,
`\sf{( - ) * ( - ) = ( + )}`

⇒
`\sf{ - 6 + 2 + 6 * 3}`

Multiply the numbers : 6 and 3

⇒
`\sf{ - 6 + 2 + 18}`

Add the numbers : 2 and 18

⇒
`\sf{ - 6 + 20}`

Calculate the difference

⇒
`\sf{14}`

Hope I helped !

Best regards!!