Question

determine what operation you would use to solve the equation.

$x + 5 = 9$
$-7 = 3 + x$
$x - 5 = 12$
$-9 + x = -15$

addition subtraction

Explanation:

Step1: Isolate $x$ for $x+5=9$

Subtract 5 from both sides: $x+5-5=9-5$

Step2: Isolate $x$ for $-7=3+x$

Subtract 3 from both sides: $-7-3=3+x-3$

Step3: Isolate $x$ for $x-5=12$

Add 5 to both sides: $x-5+5=12+5$

Step4: Isolate $x$ for $-9+x=-15$

Add 9 to both sides: $-9+x+9=-15+9$

Answer:

1. $x + 5 = 9$: Subtraction
2. $-7 = 3 + x$: Subtraction
3. $x - 5 = 12$: Addition
4. $-9 + x = -15$: Addition