Skip to main contentSkip to solution

If 2x + 3y - 8 = 0 and 3x - 2y - 12 = 0, then 4x2+y2−4x4x^2 + y^2 - 4x is equal to:

Solution

✅ Correct Option: 4

Given equations:

2x+3y−8=02x + 3y - 8 = 0 ... (1)

3x−2y−12=03x - 2y - 12 = 0 ... (2)

Rewriting:

2x+3y=82x + 3y = 8 ... (1)

3x−2y=123x - 2y = 12 ... (2)


Multiply equation (1) by 2:

4x+6y=164x + 6y = 16

Multiply equation (2) by 3:

9x−6y=369x - 6y = 36


Adding both equations:

4x+6y=164x + 6y = 16

9x−6y=369x - 6y = 36

13x=5213x = 52

x=4x = 4


Substitute x=4x = 4 into equation (1):

2(4)+3y=82(4) + 3y = 8

8+3y=88 + 3y = 8

3y=03y = 0

y=0y = 0


Substitute x=4x = 4 and y=0y = 0 into 4x2+y2−4x4x^2 + y^2 - 4x:

4x2+y2−4x4x^2 + y^2 - 4x

=4(4)2+(0)2−4(4)= 4(4)^2 + (0)^2 - 4(4)

=4(16)+0−16= 4(16) + 0 - 16

=64−16= 64 - 16

=48= 48

Therefore, 4x2+y2−4x=484x^2 + y^2 - 4x = 48.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question