Alan

As follows:

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Area of a triangle is given by (1/2)*base length*height

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m^-n is the same as 1/(m^n)

So, for example,  2^-3  is the same as 1/(2^3)  →  1/8

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Like this?

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a.  (5 + (-3))*(3 + 4) → 2*7 → 14

b.  5 + ((-3)*3 + 4*2) → 5 + (-9 + 8) → 5 + (-1) → 4

c.  (5 - 5)*6 + (7*6) - 5 → 0*6 + 42 - 5 → 0 + 42 - 5 → 37 

Usually, raising to a power takes precedence over negation so -2^2 - 4^2 is  -(2^2) - (4^2) → -4 - 16 → -20

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Hydrogen and oxygen combine to form water which is H₂O.   That is there are two atoms of hydrogen for every one of oxygen.

The atomic mass of hydrogen is 1; that of oxygen is 16.   Hence in a water molecule the total mass of hydrogen to that of oxygen is 2:16 which is the same as 1:8

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R = V/I

12 = V/8. So V = 12*8 or V = 96 (volts)

Hence. R = 96/I

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This is asking for the angle whose cosine is 1.21.  However, cosine only takes values between -1 and +1, so there is no such angle.

You could use an iterative numerical method.  Suppose you want to find the square root of the number m, say.  

Makle an initial guess x₀ (just set it to m/4 or something like it) then for a number of iterations i, use

x_i = (x_i-1 + m/x_i-1)/2   until x_i is the same as x_i-1.

For example, suppose you want to find the square root of 3:

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