Help with a Maths question!

Closed ac

Having trouble solving this, it's due for tomorrow. Help would be appreciated!

"An examination paper consists of 40 questions.
5 marks are given for each correct answer.
3 marks are deducted for each incorrect answer.
Kenny answered all 40 questions, getting x correct and getting y correct.
His total score for the exam was 56 marks."

(i) Write two equations to represent the above information.

(ii) Solve these equations to find how many questions Kenny would have answered correctly.

I can't get the answer from exam papers because I don't know what year it's from. If you could also post all your workings, that would be great!

Cheers.

Evan93

(i)
x+y=40........equation 1
5x-3y=56..........equation 2

(ii)
x+y=40.......multiply by 3
5x-3y=56

3x+3y=120
5x-3y=56

+3y and -3y cancel

8x=176

divide acros by 8

x=22

22+y=40

y=18

GO'S

DKZ wrote: »

Having trouble solving this, it's due for tomorrow. Help would be appreciated!

"An examination paper consists of 40 questions.
5 marks are given for each correct answer.
3 marks are deducted for each incorrect answer.
Kenny answered all 40 questions, getting x correct and getting y correct.
His total score for the exam was 56 marks."

(i) Write two equations to represent the above information.

(ii) Solve these equations to find how many questions Kenny would have answered correctly.

I can't get the answer from exam papers because I don't know what year it's from. If you could also post all your workings, that would be great!

Cheers.

it that book two?

Closed ac

Evan93 wrote: »

(i)
x+y=40........equation 1
5x-3y=56..........equation 2

(ii)
x+y=40.......multiply by 3
5x-3y=56

3x+3y=120
5x-3y=56

+3y and -3y cancel

8x=176

divide acros by 8

x=22

22+y=40

y=18

Thanks! I couldn't get that second equation!

Closed ac

Any chance of some help with these two also..

Maths isn't my best subject.

(i) Express in its simplest form:

2x-[3-(4-3x)]+6

(ii) Simplify:

2x²+4x-30

---

x-3

eVeNtInE

This post has been deleted.

padocon

DKZ wrote: »

Any chance of some help with these two also..

Maths isn't my best subject.

(i) Express in its simplest form:

2x-[3-(4-3x)]+6

(ii) Simplify:

2x²+4x-30

---

x-3

2x-1(3-1(4-3x))=6
2x-1(-3-4+3x)) =6
2x+3+4-3x=6
6x +7=6
6x=6-7
6x=-1
x=
-1

---

6


I am wrong! Its so hard to do it on the computer!

bluejay14

(i.) 2x-[3-(4-3x)]+6 multiply inside brackets
2x-[3-4+3x]+6 multiply next set of brackets
2x-3+4-3x+6 put like terms together

Answer=-x+7


(ii.)2x^2+4x-30

---

x-3

(2x+10)(x-3) factorise

---

(x-3) (x-3) cancels with (x-3)

Answer=2x+10

Closed ac

Thanks for your help guys! I really appreciate it.

coldwood92

skool .ie should help if maths isn't best subject in school .i op

Or
Revisewise

HL or OL?

Closed ac

coldwood92 wrote: »

skool .ie should help if maths isn't best subject in school .i op

Or
Revisewise

HL or OL?

HL

jumpguy

eVeNtInE wrote: »

(i) I think it's this:

2x-[3-(4-3x)]+6
2x-[3-4+3x]+6
2x-3+4-3x+6
-x+7

(ii)
2x²+4x-30

---

x-3

(2x+10)(x-3)

---

(x-3)

The two (x-3)'s cancel

2x+10
x+5

Think that's probably it for both of them.

I would agree!

eVeNtInE wrote: »

This post has been deleted.

It's a "simplify" question, not a "solve". Simplify means get it into it's smallest form and solve means find x.

Best way to learn maths is practice, if you can't do one in the exam papers, go onto the marking schemes. Most of the time they're fully done out on it, with a complete explanation of how it's marked (obviously.) BUT don't just copy the answers off the screen, make sure you understand where you made the mistake and how not to do it in the future!