Simplify:

(a) $15-7$and $15+\left(-7\right)$

(b) $-14-8$and $-14+\left(-8\right)$

(c) $4-\left(-19\right)$and $4+19$

(d)$-4-\left(-7\right)$and$-4+7$

Consider the given expressions $15-7$and $15+\left(-7\right)$.

Subtract 7 from 15 to obtain the value of the expression $15-7$.

$15-7=8$

The subtraction property states that $a+\left(-b\right)=a-b$.

To simplify $15+\left(-7\right)$, use the subtraction property.

$\begin{array}{rcl}15+\left(-7\right)& =& 15-7\\ & =& 8\end{array}$

The values obtained are $15-7=8$and $15+\left(-7\right)=8$.

Consider the given expressions $-14-8$and $-14+\left(-8\right)$.

Subtract 8 from $-14$to find the value of the expression $-14-8$.

$-14-8=-22$

The subtraction property states that $a+\left(-b\right)=a-b$.

To simplify $-14+\left(-8\right)$, use the subtraction property.

$\begin{array}{rcl}-14+\left(-8\right)& =& -14-8\\ & =& -22\end{array}$

The values obtained are $-14-8=-22$and $-14+\left(-8\right)=-22$.

Consider the given expressions $4-\left(-19\right)$and $4+19$.

Subtract $-19$from 4 to obtain the value of $4-\left(-19\right)$.

$4-\left(-19\right)=23$

Add 4 and 19 to obtain the value of the expression $4+19$.

$4+19=23$

The values obtained are $4-\left(-19\right)=23$and $4+19=23$.

Consider the given expressions $-4-\left(-7\right)$and $-4+7$.

Subtract $-7$from $-4$to obtain the value of $-4-\left(-7\right)$.

$-4-\left(-7\right)=3$

Add $-4$to 7 to obtain the value of $-4+7$.

$-4+7=3$

The values obtained are $-4-\left(-7\right)=3$and $-4+7=3$.