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Why is my answer incorrect?

Check for any silly mistakes, a lost negative or a simple arithmetic error. If you can’t find any, we’ll work through the question together and see where the method differs from yours. Then we will work o...

Answered by Zachary G. • Maths tutor

3034 Views

There are 9 counters in a bag. 7 of the counters are green. 2 of the counters are blue. Ria takes at random two counters from the bag. Work out the probability that Ria takes one counter of each colour. You must show your working.

Probability that Ria takes Green then Blue is 7/9 * 2/8 = 14/72. Probability that Ria takes Blue then Green is 2/9 * 7/8 = 14/72. Added together we get 28/72 = 7/18.

Answered by Zachary G. • Maths tutor

13708 Views

If 3x^2 = 48 find x

3x^2 = 48 x^2 = 16 x = 4

Answered by Frankie L. • Maths tutor

2836 Views

∫ (ln(x)/(x*(1+ln(x))^2) dx

use u = 1+ln(x) as the substitution du/dx = 1/xdx = x du ∫ (ln(x)/(x*(1+ln(x))^2) dx = ∫ ((u-1)x/ x(u^2)) du = ∫ (u-1)/(u^2) du

Answered by Jack B. • Maths tutor

7908 Views

Find the inverse function of f(x)=5/(x-4)

f(x) = 5/(x-4)To find the inverse, replace f(x) with y: y=5/(x-4)Now the aim is to make x the subject of the equation:Multiply both sides by x-4:y(x-4)=5Divide by y:x-4=5/yAnd finally add 4:x=5/y + 4

Answered by Katy M. • Maths tutor

5651 Views