18r-10r-20r+2r+9r=18
The correct answer and explanation is:
Let’s solve the equation step by step:
The given equation is: 18r−10r−20r+2r+9r=1818r – 10r – 20r + 2r + 9r = 18
Step 1: Combine like terms
All the terms on the left-hand side are terms with the variable rr. Let’s combine them: 18r−10r−20r+2r+9r18r – 10r – 20r + 2r + 9r
Adding and subtracting the coefficients of rr: (18−10−20+2+9)r=18(18 – 10 – 20 + 2 + 9)r = 18 (18−10=8)(18 – 10 = 8) (8−20=−12)(8 – 20 = -12) (−12+2=−10)(-12 + 2 = -10) (−10+9=−1)(-10 + 9 = -1)
So, the equation simplifies to: −1r=18-1r = 18
Step 2: Solve for rr
Now, to isolate rr, divide both sides of the equation by −1-1: r=18−1r = \frac{18}{-1} r=−18r = -18
Final Answer:
The value of rr is −18-18.
Explanation:
This problem involves combining like terms and then solving for the variable. First, we combined all the rr-terms on the left-hand side of the equation. After that, we simplified the terms by adding and subtracting the coefficients. Finally, we solved for rr by isolating it on one side of the equation through division.