Question

The equation 3(2x+2)-3x-15 models the change in water level in a lake in one month. Solve for x, which is change in height in inches. A. x=-7

B. x=-17/3 C. x=3 D. x= 7

Answer 1

After expanding and combining like terms in the equation 3(2x+2)-3x-15, we find that x = 3, which represents the change in height in inches of the water level in a lake. The correct answer is therefore option C.

Step-by-step explanation:

To solve the equation 3(2x+2)-3x-15 for x, which represents the change in height in inches, we first expand the equation and then collect like terms. Next, we isolate x on one side of the equation to find its value.

Here is a step-by-step solution:

1. Expand the equation: 3(2x+2) - 3x -15 = 6x + 6 - 3x - 15.
2. Combine like terms: 6x - 3x + 6 - 15 = 3x - 9.
3. Add 9 to both sides: 3x - 9 + 9 = 0 + 9, so 3x = 9.
4. Divide both sides by 3: 3x/3 = 9/3, hence x = 3.

This gives us the solution x = 3, which corresponds to option C.