Question

If 4−5=−12 and y = 3, what is x ?

Answer 1

Substituting y=3 in 4x-5y=-12 we get:

`4x-5\cdot3=-12.`

Simplifying the above equation we get:

`4x-15=-12.`

Adding 15 to the above equation we get:

`\begin{gathered} 4x-15+15=-12+15, \\ 4x=3. \end{gathered}`

Finally, dividing the above equation by 4 we get:

`\begin{gathered} (4x)/(4)=(3)/(4), \\ x=(3)/(4)\text{.} \end{gathered}`

Answer: If 4x-5y=-12 and y=3 then:

`x=(3)/(4)\text{.}`