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Solve for x, y, and z: 5x - 2y = 19 , 3x + 3z = 21 , y + z = 2

Like when there are two unknowns, the best way to solve this kind of problem is to rearrange and substitute, but because there are three unknowns, it's a bit more fiddly. To solve this you want to pick and i...
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Answered by Dan T. • Maths tutor
8267 Views

Shower-cleaner liquid is sold in spray bottles. The volume of liquid in a bottle may be modelled by a normal distribution with mean 955 ml and a standard deviation of 5 ml. Determine the probability that the volume in a particular bottle is:

a) at most 960 ml Let X be the volume of liquid in a particular bottle, then we want to find P(X <= 960). We first need to transform from X to Z (to the standard normal distribution) so that we can use th...
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Answered by Sarah S. • Maths tutor
6907 Views

A gym has 275 members. 40% are bronze members. 28% are silver members. The rest are gold members. Work out the number of gold members.

Firstly, we can calculate the total percentage of gold members = Total - bronze - silver Therefore, %gold = 100% - 40% - 28% = 32% So we know that 32% of 275 members are gold, and to find the total number of...
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Answered by Sarah S. • Maths tutor
10889 Views

How to calculate sin, cos and tan

SOH CAH TOA (imagining each as a triangle) S = sin C = cos T = tan O = opposite H = hypotenuse A = adjacent
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Answered by Phoebe H. • Maths tutor
3749 Views

Use the product rule to differentiate y=2xsinx

The product rule states that y=uv and dy/dx=(u)dv/dx + (v)du/dx. As the equation is in this form we can let u=2x and v=sinx. Therefore du/dx=2 and dv/dx=cosx. Substituting for u and v we get dy/dx=(2x)(cosx)...
GK
Answered by Georgianna K. • Maths tutor
15822 Views