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If x>2y and 2x<5y, what is the range of x when y=6?

x &gt; (2x6) :. x &gt; 12 2x &lt; (5x6) :. 2x &lt; 30 :. x &lt; 15 12 &lt; x &lt; 15
MB
Answered by Michael B. • Maths tutor
3558 Views

Sean wants to go on holiday. He is going to get a loan of £ 720 to help pay for the holiday. Sean will have to pay back the £ 720 plus interest of 15 %. He will pay this back in 12 equal monthly installments. How much money will Sean pay back each month?

Sean is lent £720. He has to pay back all of this, plus the extra 15% interest. So first you have to find 15% of £720: 10% is £72, 5% is £36, therefore 15% is £72 + £36 = £108. The total amount he has to pay...
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Answered by Emma L. • Maths tutor
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Solve the equation 2ln2x = 1 + ln3. Give your answer correct to 2dp.

LHS: because alnx = lnx a , 2ln2x = ln(2x) 2 = ln4x 2 Now, because ln and e are inverse functions, we take both sides to the power of e. Therefore: e ln4x^2 = e 1 + ln3 4x 2 = e 1 + ln3 x 2 = (e 1 + ln3 ) / ...
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Answered by Shiv S. • Maths tutor
5189 Views

The number of uniform spherical balls that can be produced from a given mass of lead is inversely proportional to the radius of the ball cubed. If 2744 balls can be made when the radius is 1mm, how many balls can be made when the radius is 1.4mm ?

So first we need to write down the proportionality relationship the question states. If we let n be the number of balls and r be the radius of the balls we can say n (proportional symbol) 1/r 3 . We can turn...
TC
Answered by Tabraiz C. • Maths tutor
3631 Views

Integrate ⌠( xcos^2(x))dx

We must first use trigonometric identities to simplify cos 2 (x). We can use the formula cos(A+B) = cos(A)cos(B) - sin(A)sin(B) , where A=x and B=x , so that we get cos(2x) = cos 2 (x) - sin 2 (x) = 2cos 2 (...
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Answered by Daniel A. • Maths tutor
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