The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

Maths Quadratic Equation Help

How would I do the following question:

Show that 2x^2+6x-95=0

Thanks
Reply 1
Avatar for SL2310
SL2310
4
Original post by JamieSUFC
How would I do the following question:

Show that 2x^2+6x-95=0

Thanks


I helped my friend answer this question today loool!
Shouldn't there be a L shape with length containing numbers and algebra? Like x+4cm for instance or 5 cm.
Reply 2
Avatar for JamieSUFC
JamieSUFC
OP
Original post by SL2310
I helped my friend answer this question today loool!
Shouldn't there be a L shape with length containing numbers and algebra? Like x+4cm for instance or 5 cm.


Yeah 2 rectangles one labelled with 5 and x, the other x and 2x+1.
Reply 3
Avatar for Parallex
Parallex
6
Original post by JamieSUFC
How would I do the following question:

Show that 2x^2+6x-95=0

Thanks


The area of the shape is 95cm2.
This is shown by: Rectangle on the left (area) being x*5=5x
Rectangle on the right (area) being 2x+1*x=2x2+x
2x2+x+5x=2x2+6x

Therefore...
2x2+6x=95
So subtracting 95 makes it equal to 0.
Reply 4
Avatar for Blobar
Blobar
15
Original post by Parallex
The area of the shape is 95cm2.
This is shown by: Rectangle on the left (area) being x*5=5x
Rectangle on the right (area) being 2x+1*x=2x2+x
2x2+x+5x=2x2+6x

Therefore...
2x2+6x=95
So subtracting 95 makes it equal to 0.


That isn't what the OP asked for lol. Use the quadratic formula.
Reply 5
Avatar for Parallex
Parallex
6
Original post by Blobar
That isn't what the OP asked for lol. Use the quadratic formula.


Actually, it is. The question after that asks you to solve. There's a difference between solving and showing.
Reply 6
Avatar for Blobar
Blobar
15
Original post by Parallex
Actually, it is. The question after that asks you to solve. There's a difference between solving and showing.


Oh wait sorry I didn't quite read the OPs post and just assumed. My bad.
Reply 7
Avatar for JamieSUFC
JamieSUFC
OP
Original post by Parallex
The area of the shape is 95cm2.
This is shown by: Rectangle on the left (area) being x*5=5x
Rectangle on the right (area) being 2x+1*x=2x2+x
2x2+x+5x=2x2+6x

Therefore...
2x2+6x=95
So subtracting 95 makes it equal to 0.


Thanks :smile:

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you