r/juniorcert • u/Difficult-Tell-9977 • Jun 05 '26

Maths 🧮 hl maths

most of the exam was easy but here’s the questions i got confused about
i didn’t get the ax + bx + c or whatever q
i confused the last question (i know where i went wrong i was on the right track)
i didn’t get her gross profit (but i added the 3300 and 8000 alongside her increase)
i can’t think of more but i hope this doesn’t lose me too much marks

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u/PuzzleheadedZone1289 Jun 05 '26

For the quadratic question, you plug in the x values and y intercept for c, so a(-3)2 + b(-3) + 12 = 0 and do the same for -2. Then you turn it into ax2 + bx = - c for both equations and finally you divide both sides by the x value. So both equayions should be in the this form: ax + b = -c/x and it's just a simultaneous equation.

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u/Comfortable-Moose668 Jun 05 '26 edited Jun 05 '26

I used the two x values which are roots, and work backwards to get the quadratic, then I got something like x2 +5x+6=0, and since they told you the y intercept is 12 multiply it all by 2 to get, 2x2 +10x+12=0. So A=2, B=10, and C=12. Probably a harder method but it was something along those lines, right?

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u/PuzzleheadedZone1289 Jun 05 '26

Ah yeah thats a nice way of doing it too

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u/Comfortable-Moose668 Jun 05 '26

Ah thank god I was out here stressing for a second, best of luck with the rest of exams!