The way you want to do this is to make all the numbers into a fraction. You do that by multiplying the whole number by the denominator, or the bottom of the fraction, then adding that to the numerator, or the top of the fraction.

So, $4\frac{1}{2}$ becomes $\frac{9}{2}$ , and $2\frac{3}{4}$ becomes $\frac{11}{4}$ .

Then, you find the least common denominator. The least common denominator (LCD) is the smallest number that can be a common denominator for a set of fractions. In our case, that would be 4, since 2 can multiply into 4.

So, $\frac{9}{2}$ is multiplied by 2, and becomes $\frac{18}{4}$ . $\frac{11}{4}$ stays the same.

And finally, you subtract. When subtracting or adding fractions, you leave the denominator alone, and only work with the top number.

So, $\frac{18}{4}-\frac{11}{4}$ , which equals $\frac{7}{4}$ .

Now, you could technically stop there. However, most teachers ask that you put it back into whole number form. To do that, divide the numerator by the denominator, and whatever remains goes back into the fraction.

So, $\frac{7}{4}=1\frac{3}{4}$

That's your answer! Hope this helps.

8 0

3 years ago

If it takes 15 minutes to dry your hair with a 1.200 kW hair drier, how much energy is used in drying your hair?

slega [8]

E=Pt where e= energy P= power t= time

E=1.200kiowatt/15 minutes
E={1200/100*1000}/15
E=800 watt/minute

5 0

3 years ago