Solving Equations by using Addition/ Subtraction: Complete the missing number

First, we solve the multiplication exercise:

$12\times(-6)=-72$

Now we get:

$23-(-72)+x\colon7=102$

Let's pay attention to the minus signs, remember that a negative times a negative equals a positive.

We multiply them one by one to be able to open the parentheses:

$23+72+x\colon7=102$

We reduce:

$95+x:7=102$

We move the sections:

$x:7=102-95$

$x:7=7$

$\frac{x}{7}=7$

Multiply by 7:

$x=7\times7=49$

We begin by solving the innermost parentheses:

$94-73=21$

We obtain the following calculation:

$x\colon(-6)+\lbrack-2(21)\rbrack=-153$

Next we focus on the parentheses and multiply:

$-2\times21=-42$

We obtain the following calculation:

$x\colon(-6)+(-42)=-153$

Let's consider the multiplication between minus and plus:

$x\colon(-6)-42=-153$

We swap sections:

$x\colon(-6)=-153+42$

$x\colon(-6)=-111$

$\frac{x}{-6}=-111$

Lastly we multiply by minus 6:

$x=-111\times-6=666$

First, we place the multiplication exercise inside of parentheses:

$x\colon4+(8\times3)-7=26$

Next we solve the multiplication exercise:

$x\colon4+24-7=26$

We then place the subtraction exercise in parentheses:

$x\colon4+(24-7)=26$

We solve the subtraction exercise:

$x\colon4+17=26$

We swap sections:

$x\colon4=26-17$

$\frac{x}{4}=9$

Multiply by 4

$x=4\times9=36$

We place the multiplication exercise inside of the parenthesis:

$(5\times17)-112-\frac{x}{14}=-27.5$

We solve the multiplication exercise and then subtract:

$85-112-\frac{x}{14}=-27.5$

$-27-\frac{x}{14}=-27.5$

We swap sections:

$-\frac{x}{14}=-27.5+27$

$-\frac{x}{14}=-\frac{1}{2}$

We multiply by 14:

$-x=-\frac{1}{2}\times14$

$-x=-7$

We multiply by -1

$x=7$

We solve the exercise in parentheses:

$23\times19+25\colon5+?\times3=82$

We place the multiplication and division exercises inside parentheses:

$(23\times19)+(25\colon5)+?\times3=82$

We solve the exercise in parentheses:

$437+5+?\times3=82$

We simplify:

$442+?\times3=82$

We swap sections:

$?\times3=82-442$

$?\times3=-360$

We divide by 3

$?=-120$