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Describe and explain how the reactivity of the elements changes as you go down group 1

As you go down group 1, the reactivity increases. This is because each element has only one electron in their outer shell, so need to lose this electron in order to react. As you go down group 1, the number ...
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Answered by Edward S. • Chemistry tutor
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ln(2x^2 +9x-5) =1+ ln( x^2+2x-15)

Moving Ln to one side ln(2x^2 +9x-5) - ln( x^2+2x-15) =1 Subtracting Ln is the same as dividing ln(((2x^2 +9x-5)/( x^2+2x-15)) ln((2x-1)/(x-3))=1 Taking e to both sides (2x-1)/(x-3)=e x=(1-3e)/(2-e)
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Answered by Raj H. • Maths tutor
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Clare buys some shares for $50x. Later, she sells the shares for $(600 + 5x). She makes a profit of x% (a) Show that x^2 + 90x − 1200 = 0

Profit is (New price-Original price)/Original price . As a fraction it is percentage Profit/100. Equate (New price-Original price)/Old Profit to the fraction of Profit in %/100. Cross multiply and come up wi...
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Answered by Raj H. • Maths tutor
13111 Views

The nth term of a sequence is 8(2^n + 2^(6n-7)). a) Without a calculator, find the 2nd term of this sequence, b)​​​​​​​ Express the formula in the form 2^x + 2^y

To find a) just plug in the number two to all places where n appears. In this case 8(2^2 + 2^(6 * 2 - 7)) and then number crunch. 8(4+2^5) -> 8 * (4 + 32) -> 8 * 36= 288. To find part b, we must first ...
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Answered by Tom P. • Maths tutor
5338 Views

Simplify fully: (7x^2 - 21x)/(x^2 + 2x - 15)

This one is quite complicated to answer typed up like this and i would definitley use a white board Show that 7x^2 - 21x can be come x(7x-21) which can in turn become 7x(x-3) Show that x^2 + 2x - 15 can beco...
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Answered by Dominic G. • Maths tutor
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