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A 4 pint bottle of milk costs £1.18 A 6 pint bottle of milk costs £1.74 Which bottle of milk is the best value for money? You must show all your working.

To work out which bottle is best value for money you have to work out how much each bottle costs per pint. To do this divide the cost of each bottle by the number of pints it contains. e.g 1.18/4=0.295 1.74/...
AP
Answered by Amelia P. • Maths tutor
23360 Views

Make x the subject of 5(x-3) = y(4-3x)

First expand out the brackets: 5x-15 = 4y -3xy Then re-arrange to bring all the x terms to one side: 5x+3xy = 4y +15 Now factorise: x(5+3y) = 4y + 15 Now we have isolated the x term, we can divide both sides...
AI
Answered by Alisha I. • Maths tutor
19837 Views

Solve the ODE y' = -x/y.

we have dy/dx = -x/y , so we treat the differentials as fractions and write y dy = -x dx. Now integrating the left side with respect to y and the right side with respect to x, we have y 2 /2 = -x 2 /2 + C. W...
JM
3728 Views

How do I multiply and divide indices?

First you need to understand what an index (or power) is. It’s just a compact way of writing a number multiplied by itself a number of times. For example: 3 4 = 3x3x3x3 and a 2 = axa. If two indices have the...
SM
Answered by Sarah M. • Maths tutor
14261 Views

I've been told that I can't, in general, differentiate functions involving absolute values (e.g. f(x) = |x|). Why is that?

When you differentiate a function which has only one parameter, like f(x), you are finding a new function, f'(x), which gives the gradient of your original function at every point. You'll probably remember t...
RW
Answered by Richard W. • Maths tutor
3491 Views