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x^2 - x - 90 = 0. Solve to find x.

Comparing to this to ax^2 + bx + c = 0, you'll find that a=1, b=-1, c=90. You need to split b (in this case -1), into two numbers that add up to b (-1), and multiply to ac (90). -> These are -10 and 9. No...
YL
Answered by Yanakan L. • Maths tutor
4511 Views

Express x^2 + 5x + 10 in the form (x+p)^2 +q

x^2+5x+10 -> (x+p)^2+q (x+5/2)^2 - (5/2)^2 + 10 (x+5/2)^2 - (25/4) +40/4 (x+5/2)^2 +15/4
IB
Answered by Imogene B. • Maths tutor
6519 Views

There are 30 balls in the bag, 10 of which are blue. Adam takes 2 balls out of the bag without a replacement and calculated that there is a probability of 0.2 of both balls being blue. What percentage error did he make compared to the true probability?

True probability of 2 consecutive balls picked being blue: (10/30)*(9/29)=3/29 which is 0.1034 (4 d.p.) 3/29-100% 0.2-x% so, x=0.2*100/(3/29)= 193.3 (1 d.p.) therefore Adam's result is 93.3 % (1 d.p.) over t...
DK
Answered by Deimena K. • Maths tutor
3839 Views

Solve 7x=4(x-8)

The first thing you need to do to make this easier is to multiply out the brackets so that you can then move all the 'x' terms to one side and all the numbers to the other side. It would become: 7x=4x-32 You...
MU
Answered by Megha U. • Maths tutor
5873 Views

How do you find the HCF of 110 and 132

Draw a diagram breaking down 110 and 132 into their multiples (on whiteboard), e.g. 110=11 10 132=11 12 Circle the prime numbers, 11, and then break down the composite numbers (those that aren't prime) into ...
JJ
Answered by Josiah J. • Maths tutor
18959 Views