Urgent help needed with maths questions!!!!!!!!!?

1. (a) (i) Use a factor tree to write 630 as a product of prime factors.


(ii) Calculate 2/3 + 1/5 - 1/6, leaving your answer as a fraction in its simplest form, showing all


of your working.


(iii) Simplify the square root of 28 by writing it as a product of an integer and a surd in its


simplest form, show all of your working.





(b) A group of 1260 students take a test. 1120 pass the test and 140 fail it.


(i) Write down the ratio of the number of students who pass the test to the number of students


who fail. Simplify this as far as possible.


(ii) One of the questions in the test is a multiple choice question with four options, A, B, C and


D. The number of students choosing the options A, B, C, and D are in the ratio


3 : 1 : 2 : 14. Calculate the number of students choosing each option. Explain how you


could check that your answers are correct.








2. (a) For each of the following expressions, multiply out any brackets and simplify as far as


possible.


(i) 3m - 8 - 5m + 10


(ii) 4(2 - 6f)


(iii) 7(a + 3) - 5


(iv) 2f - 3(4y - f)


(v) 2(4y - 1) + 5y(3 - 2y)





(b) Solve the following equations, show your working.


(i) 7f + 9 = 5f - 5


(ii) f/3 + 15 = 3(f - 11)








3. In this final question, I ask you to comment critically on a student's incorrect attempt at solving the equation 2(f + 3) = 2. The attempt is shown below:





The equation is: 2(f + 3) = 2


Multiply out the brackets: 2f + 3 = 2


Subtract 3: 2f + 3 - 3 = 2


Divide by 2: 2f = 2


The solution is: f = 1





(a) Substitute the students answer f = 1 into the left hand of the equation 2(f + 3) = 2. Explain why this shows that the student's answer is incorrect.


(b) Write out your own solution to the equation, explaining your working thoroughly.


(c) Explain briefly two mistakes made by the student.Urgent help needed with maths questions!!!!!!!!!?
1.a ) i) 630 = 2 * 3 * 3 * 5 * 7





1.a.ii) 2/3 + 1/5 - 1/6 = ( 2 *10 + 1 *6 - 1 * 5 ) / ( 5 * 6 ) = 21/30 = 7/10





i'm going out come back and give answers......Urgent help needed with maths questions!!!!!!!!!?
(b) A group of 1260 students take a test. 1120 pass the test and 140 fail it.


(i) Write down the ratio of the number of students who pass the test to the number of students who fail.





Answer -


Pass to fail ratio = 1120 / 140 or, 8





ii) One of the questions in the test is a multiple choice question with four options, A, B, C and


D. The number of students choosing the options A, B, C, and D are in the ratio


3 : 1 : 2 : 14. Calculate the number of students choosing each option. Explain how you


could check that your answers are correct.





Answer -





Total no. of student taking the test - 1260


ABCD ratio = 3 : 1 : 2 : 14


Total of the ratio = 3+1+2+14 = 20


No. of students choosing A = 3/20 * 1260 = 189


No. of students choosing B = 1/20 * 1260 = 63


No. of students choosing C = 2/20 * 1260 = 126


No. of students choosing D = 14/20 * 1260 = 882








The other questions are difficult....sorry......
1.a(ii) 1. solve 2/3+1/5 first..n u will get13/15...after that, solve 13/15-1/6..then the answer is 7/10..





2 a.i.rearrange the equation first..3m-5m-8+10..then u will get -2m+2..factorize...u will get 2(1-m)..


ii) answer: 1-3f


iii) 7a+16