Question

4 exercises 18 through 29 user algorithm of five each difference without using a calculator show your work

Answer 1

Exercise 18 says:

$^+12-^+4$

to solve this we do substract 12 from 4, because both digits have different signs, like this

$^+12-^+4=^+8$

Th sign of the result is the sign of the larger number

For exercice 19, we have

$^+12-^+12$

we subtract 12 from 12, we get zero, that is:

$^+12-^+12=0$

the same is done for exercices 20, 21, 22, 23, 24 and 25

For exercice 27 we have

$\frac{^+1}{2}-\frac{^+3}{4}$

To do this exercice, we will first multiply the numerator and denominator of the left fraction by a number in such a way that each denominator are the same, in this case we will multiply by 2/2, like this:

$^{}\frac{^{+^{}}1}{2}(\frac{2}{2})-\frac{^{+^{}}3}{4}$$\frac{^+2}{4}-\frac{^+3}{4}$

Since the denominators are the same, for the result we puit the same denominator and perform the operation for the numerator, like this:

$\frac{^+2}{4}-\frac{^{+^{}}3}{4}=\frac{^+2-^{+^{}}3}{4}$

To solve the operation in the numerator, we will substract and the result should have the sign of the larger number

$\frac{^+2-^+3}{4}=\frac{^-1}{4}$

The same way is done for exercices 28 and 29, having into account that denominators must be the same and if they are not the same, then we multiply and divide one of the franctios for a numbers in such a way that they become the same.