which methods correctly solve for the variable x in the equation 7 - x = 18? select all that apply. first…

which methods correctly solve for the variable x in the equation 7 - x = 18? select all that apply. first, add 18 to both sides. then, multiply both sides by - 1. first, subtract x from both sides. then, multiply both sides by 18. first, add x to both sides. then, subtract 7 from both sides. first, add x to both sides. then, subtract 18 from both sides. first, subtract 7 from both sides. then, multiply both sides by - 1.
Answer
Explanation:
Step1: Analyze the equation $7 - x=18$
We want to isolate $x$.
Step2: Option - by - option analysis
Option 1: First, add 18 to both sides. Then, multiply both sides by - 1.
Adding 18 to both sides gives $7 - x+18=18 + 18$, or $25 - x=36$, which is not a correct first - step to isolate $x$.
Option 2: First, subtract $x$ from both sides. Then, multiply both sides by 18.
Subtracting $x$ from both sides gives $7 - x-x=18 - x$, or $7-2x = 18 - x$, which is not a correct way to isolate $x$.
Option 3: First, add $x$ to both sides. Then, subtract 7 from both sides.
Adding $x$ to both sides: $7 - x+x=18 + x$, so $7=18 + x$. Subtracting 7 from both sides: $7-7=18 + x-7$, we get $0 = 11 + x$, then $x=-11$. This is a correct method.
Option 4: First, add $x$ to both sides. Then, subtract 18 from both sides.
Adding $x$ to both sides: $7 - x+x=18 + x$, so $7=18 + x$. Subtracting 18 from both sides: $7-18=18 + x-18$, we get $- 11=x$. This is a correct method.
Option 5: First, subtract 7 from both sides. Then, multiply both sides by - 1.
Subtracting 7 from both sides: $7 - x-7=18 - 7$, so $-x = 11$. Multiplying both sides by - 1 gives $x=-11$. This is a correct method.
Answer:
First, add $x$ to both sides. Then, subtract 7 from both sides. First, add $x$ to both sides. Then, subtract 18 from both sides. First, subtract 7 from both sides. Then, multiply both sides by - 1.