Answer:
u = -5/9
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
- Equality Properties
Step-by-step explanation:
<u>Step 1: Define equation</u>
-3(u + 2) = 5u - 1 + 5(2u + 1)
<u>Step 2: Solve for </u><em><u>u</u></em>
- Distribute: -3u - 6 = 5u - 1 + 10u + 5
- Combine like terms: -3u - 6 = 15u + 4
- Add 3u to both sides: -6 = 18u + 4
- Subtract 4 on both sides: -10 = 18u
- Divide 18 on both sides: -10/18 = u
- Simplify: -5/9 = u
- Rewrite: u = -5/9
<u>Step 3: Check</u>
<em>Plug in u into the original equation to verify it's a solution.</em>
- Substitute in <em>u</em>: -3(-5/9 + 2) = 5(-5/9) - 1 + 5(2(-5/9) + 1)
- Multiply: -3(-5/9 + 2) = -25/9 - 1 + 5(-10/9 + 1)
- Add: -3(13/9) = -25/9 - 1 + 5(-1/9)
- Multiply: -13/3 = -25/9 - 1 - 5/9
- Subtract: -13/3 = -34/9 - 5/9
- Subtract: -13/3 = -13/3
Here we see that -13/3 does indeed equal -13/3.
∴ u = -5/9 is a solution of the equation.
Answer:
1/2
Step-by-step explanation:
The radius is 1/2 of the diameter
A direct variation is a mathematical relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other. In other words, a direct variation is where

.
In answer a,

, so it is a direct variation.
In answer c,

, so it is a direct variation.
In answer d,

, so it is a direct variation,
Only answer b is left, which means the answer must be 'b'.
We also know 'b' is the answer because it cannot be expressed as <span>

. Instead, it is expressed as </span>

, which is not the same thing and is therefore not a direct variation.
Hope I helped, and let me know if you have any questions :)