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I need help with this, I've never really understood linear stuff.


Determine which of the following points lies on the line of the linear equation y = -3x + 7.

Respuesta :

LammettHash

You have several possible points [tex](x,y)[/tex]. Any point that lies on the given line will have a [tex]y[/tex] value that you obtain by plugging in the corresponding value of [tex]x[/tex] into the equation of the line.

The line has equation [tex]y=-3x+7[/tex], so any point on the line will have the form [tex](x,-3x+7)[/tex].

Among the four given points, there are only 2 different values of [tex]x[/tex] to check. We have

[tex]x=4\implies y=-3(4)+7=-12+7=-5[/tex]

[tex]x=1\implies y=-3(1)+7=-3+7=4[/tex]

which means the given line contains the points (4, -5) and (1, 4). So the answer is A.

DeanR

OK; there's another answer but I haven't peeked.

y = -3 x + 7

A(4,-5): -3(4)+7=-12+7=-5 (4,-5) is on the line

B(4 ,19) . We got y=-5 when x=4 so this one isn't on the line.

C(1, 5) : -3(1)+7=4 not 5, not on the line

D(1, -19) : Still 4 not -19, not on the line

Answer: A