Question

2 lines 3y-2x=21 and 4y+5x=5, intersect at the point Q. Find the coordinates of Q

Answer 1

Answer: (-3,5)

Step-by-Step Solution:

1. Set 1 equation equal to y

3y-2x=21

3y=2x+21

y=2/3x+7

2. Set the other equation equal to y

4y+5x=5

4y=-5x+5

y=-5/4x+5/4

3. Set the equations equal to each other, and solve for x

2/3x+7=-5/4x+5/4

2/3x+23/4=-5/4x

(Multiply by 12 on both sides to get rid of fractions)

8x+69=-15x

8x=-15x-69

23x=-69

x=-3

4. Solve for y

(Choose any of the equations)

y=2/3x+7

y=2/3(-3)+7

y=-2+7

y=5

ANSWER: (-3,5)