Westonci.ca connects you with experts who provide insightful answers to your questions. Join us today and start learning! Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals. Join our platform to connect with experts ready to provide precise answers to your questions in different areas.

What was Dimitri's mistake? He mixed up the coordinates of the ordered pair when Substituting it into the equations 7x+9y=-4 and 5x-2y=6

Sagot :

Answer:

He made a mistake in his calculations when simplifying 5x - 2y

Step-by-step explanation:

Given

The coordinate pair

[tex](x,y) = (2,-2)[/tex]

The equations

[tex]7x + 9y = ?[/tex]

[tex]5x - 2y = ?[/tex]

Dimitri's Solution

[tex]Equation\ 1: 7x + 9y = -4.[/tex]

[tex]7(2) + 9 (-2) = -4.[/tex]

[tex]14 + (-18) = -4.[/tex]

[tex]-4 = -4.[/tex]

[tex]Equation\ 2: 5x -2y = 6.[/tex]

[tex]5(2) - 2 (-2) = 6.[/tex]

[tex]10 - 4 = 6.[/tex]

[tex]6 = 6.[/tex]

Required

Identify Dimitri’s mistake

In the first equation, Dimitri made no mistake.

However, he made a mistake when simplifying the second equation.

We have:

[tex]5x - 2y[/tex]

and

[tex](x,y) = (2,-2)[/tex]

Substitute [tex]x = 2[/tex] and [tex]y = -2[/tex]

So, we have:

[tex]5(2) -2(-2)[/tex]

Open bracket

[tex]10 +4[/tex]

Finally, we have:

[tex]14[/tex]