Question

Which ordered pairs could be used to graph the equation 2x+y=5

Answer 1

Answer: The correct answer is option D; (-2, 9), (4, -3)

Step-by-step explanation: The ordered pairs that can be used to graph an equation can best be explained as those values of x and y such that when plotted on the graph along the x and y axes, you would have a graphical solution for the equation. Just as a simultaneous equation helps you find the values that would satisfy your pair of equations, same way your ordered pairs would help you determine which values of x and y are correct for your equation on a graph.

To begin with, you take a value for x (since the pair is by standard written as [x, y] ). For the equation 2x + y = 5 we shall start with x equals 1 as follows;

If x = 1,

2(1) + y = 5

2 + y = 5

y = 5 - 2

y = 3      (1, 3)

If x = 2,

2(2) + y = 5

4 + y = 5

y = 5 - 4

y = 1       (2, 1)

If x = 3,

2(3) + y = 5

6 + y = 5

y = 5 - 6

y = -1       (3, -1)

If x = 4,

2(4) + y = 5

8 + y = 5

y = 5 - 8

y = -3       (4, -3)**

If x = 5,

2(5) + y = 5

10 + y = 5

y = 5 - 10

y = -5       (5, -5)

We shall now take the values from the negative side of the x axis.

If x = -1,

2(-1) + y = 5

-2 + y = 5

y = 5 + 2

y = 7       (-1, 7)

If x = -2,

2(-2) + y = 5

-4 + y = 5

y = 5 + 4

y = 9      (-2, 9)**

If x = -3,

2(-3) + y = 5

-6 + y = 5

y = 5 + 6

y = 11      (-3, 11)

If x = -4,

2(-4) + y = 5

-8 + y = 5

y = 5 + 8

y = 13      (-4, 13)

If x = -5,

2(-5) + y = 5

-10 + y = 5

y = 5 + 10

y = 15      (-5, 15)

From our calculations above, the pair that satisfies the equation from the options given in the question have been asterisked and these are;

(-2, 9), (4, -3)

Answer 2

Answer:

(-2,9) ,(4,-3)

Step-by-step explanation:

Given the expression 2x+y=5

We are required to look for values of x and y such that when substituted into the given expression will result in the number 5

The Pairs are (-2,9) ,(4,-3)

Let us plug in the values to check

1. (-2,9)

2(-2)+9=5

-4+9=5

5=5 true

2. (4,-3)

2(4)+(-3)=5

8-3=5

5=5 true