Question

-2(7x + 3y)=86a. (2,38)b.(1,-24)c.(-1,-12)d.(-2,-9)

Answer 1

The coordinates of a point are written in the form:

`(x,y)`

Substitute the values of x and y of each given option to check if they satisfy the equation or not.

a)

x=2 and y=38

`\begin{gathered} -2(7(2)+3(38))=86 \\ \Rightarrow-2(14+114)=86 \\ \Rightarrow-2(128)=86 \\ \Rightarrow-256=86 \end{gathered}`

This point does not satisfy the equation.

b)

x=1 and y=-24

`\begin{gathered} -2(7(1)+3(-24))=86 \\ \Rightarrow-2(7-72)=86 \\ \Rightarrow-2(-65)=86 \\ \Rightarrow130=86 \end{gathered}`

This point does not satisfy the equation.

c)

x=-1 and y=-12

`\begin{gathered} -2(7(-1)+3(-12))=86 \\ \Rightarrow-2(-7-36)=86 \\ \Rightarrow-2(-43)=86 \\ \Rightarrow86=86 \end{gathered}`

This point satisfies the equation.

d)

x=-2 and y=-9

`\begin{gathered} -2(7(-2)+3(-9))=86 \\ \Rightarrow-2(-14-27)=86 \\ \Rightarrow-2(-41)=86 \\ \Rightarrow82=86 \end{gathered}`

This point does not satisfy the equation.

Therefore, the only option which satisfies the given equation, is:

`c.(-1,-12)`