Question

use the elimination method to solve the system of equation. choose the correct ordered pair. 5x=3y+31 2x=3y+25

Answer 1

B Ordered pair ( 2 ,7).

Explanation:

Given : 5x = 3y+31 and 2x = 3y+25.

To find : use the elimination method to solve the system of equation.

Solution : We have given that

5x +3y = 31 ------(1)

2x +3y = 25-------(2)

On subtracting equation (2) from (1)

5x + 3y = 31

(-)2x +(-)3y = (-)25

__________

3x +0 = 6

3x =6

On dividing by 3 both sides

x = 2.

Now plugging the value of x = 2 in equation (1)

5 (2)+ 3y = 31

10 +3y = 31

On subtracting both sides by 10

3y = 31 -10

3y = 21

On dividing by 3 both sides

y = 7

Ordered pair ( 2 ,7).

Therefore, B Ordered pair ( 2 ,7).

Answer 2

B. (2, 7)

Explanation:

(1) 5x + 3y = 31

(2) 2x + 3y = 25 Subtract (2) from (1)

3x = 6 Divide each side by 3

x = 2 Substitute in (2)

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4 + 3y = 25 Subtract 4 from each side

3y = 21 Divide each side by 3

y = 7

The solution is (2, 7).

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Check:

(1) 5×2 + 3×7 = 31

10 + 21 = 31

31 = 31

(2) 2×2 + 3×7 = 25

4 + 21 = 25

25 = 25