12(1.2x+4.65)=15(x+3.5)

11 answers

To solve the equation \( 12(1.2x + 4.65) = 15(x + 3.5) \), we start by distributing both sides.

Step 1: Distribute on both sides.

Left side: \[ 12(1.2x) + 12(4.65) = 14.4x + 55.8 \]

Right side: \[ 15(x) + 15(3.5) = 15x + 52.5 \]

Now the equation looks like: \[ 14.4x + 55.8 = 15x + 52.5 \]

Step 2: Move all terms involving \( x \) to one side and constant terms to the other side.

Subtract \( 14.4x \) from both sides: \[ 55.8 = 15x - 14.4x + 52.5 \]

This simplifies to: \[ 55.8 = 0.6x + 52.5 \]

Subtract \( 52.5 \) from both sides: \[ 55.8 - 52.5 = 0.6x \]

This simplifies to: \[ 3.3 = 0.6x \]

Step 3: Solve for \( x \).

To isolate \( x \), divide both sides by \( 0.6 \): \[ x = \frac{3.3}{0.6} \]

Calculating this gives: \[ x = 5.5 \]

So the solution to the equation \( 12(1.2x + 4.65) = 15(x + 3.5) \) is: \[ \boxed{5.5} \]

A group of 6 friends went ice-skating. They each paid an admission fee of $x and $2.50 for hot chocolate. Another group of 5 friends went ice-skating at a different rink, and they paid 1.5 times as much for admission as the first group. The group of 5 friends spent $2.25 each for hot chocolate. The two groups paid the same total amount. What did each of the first group of friends pay for admission?

Let's denote the admission fee that each of the first group of friends paid as \( x \). Since there are 6 friends in that group, the total amount they paid for admission is:

\[ 6x \]

Each friend in the first group also paid $2.50 for hot chocolate, so the total amount spent by the first group on hot chocolate is:

\[ 6 \times 2.50 = 15.00 \]

Thus, the total amount spent by the first group on both admission and hot chocolate is:

\[ 6x + 15.00 \]

For the second group of 5 friends, they paid 1.5 times as much for admission as the first group. Therefore, the admission fee per person for the second group is:

\[ 1.5x \]

The total amount the second group paid for admission is:

\[ 5 \times 1.5x = 7.5x \]

Each friend in the second group paid $2.25 for hot chocolate, so the total amount spent by the second group on hot chocolate is:

\[ 5 \times 2.25 = 11.25 \]

So, the total amount spent by the second group on both admission and hot chocolate is:

\[ 7.5x + 11.25 \]

Since the two groups paid the same total amount, we can set the two total amounts equal to each other:

\[ 6x + 15.00 = 7.5x + 11.25 \]

Step 1: Rearranging the equation

To solve for \( x \), we can rearrange the equation by subtracting \( 6x \) and \( 11.25 \) from both sides:

\[ 15.00 - 11.25 = 7.5x - 6x \]

This simplifies to:

\[ 3.75 = 1.5x \]

Step 2: Solving for \( x \)

Next, we can solve for \( x \) by dividing both sides by \( 1.5 \):

\[ x = \frac{3.75}{1.5} \]

Calculating this gives:

\[ x = 2.5 \]

Thus, the admission fee that each of the first group of friends paid is:

\[ \boxed{2.50} \]

Emma walks around a rectangular city block. She walks a total of 380 yards. The length of the block is 10 yards longer than the width. What is the width of the city block?

Let's denote the width of the rectangular city block as \( w \) yards. According to the problem, the length of the block is \( w + 10 \) yards.

The perimeter \( P \) of a rectangle is given by the formula:

\[ P = 2(\text{length} + \text{width}) \]

Substituting for the length and width, we have:

\[ P = 2((w + 10) + w) \]

Simplifying this expression:

\[ P = 2(2w + 10) = 4w + 20 \]

We know from the problem that Emma walks a total of 380 yards around the block, thus:

\[ 4w + 20 = 380 \]

Step 1: Solve for \( w \)

First, we subtract 20 from both sides:

\[ 4w = 380 - 20 \] \[ 4w = 360 \]

Now, divide both sides by 4:

\[ w = \frac{360}{4} \] \[ w = 90 \]

Thus, the width of the city block is:

\[ \boxed{90 \text{ yards}} \]

Step 2: Check the dimensions

To ensure our calculations are correct, let's find the length:

\[ \text{Length} = w + 10 = 90 + 10 = 100 \text{ yards} \]

Now, we can calculate the perimeter again to verify:

\[ P = 2(\text{length} + \text{width}) = 2(100 + 90) = 2 \times 190 = 380 \text{ yards} \]

The calculated perimeter matches the total distance Emma walked, confirming our solution is correct. Thus, the width of the city block remains:

\[ \boxed{90 \text{ yards}} \]

2(4x-7)=66

To solve the equation \( 2(4x - 7) = 66 \), we can follow these steps:

Step 1: Distribute the left side

Distributing the \( 2 \) gives us:

\[ 8x - 14 = 66 \]

Step 2: Add 14 to both sides

Next, we add \( 14 \) to both sides of the equation:

\[ 8x - 14 + 14 = 66 + 14 \] \[ 8x = 80 \]

Step 3: Divide both sides by 8

Now, we divide both sides by \( 8 \) to solve for \( x \):

\[ x = \frac{80}{8} \] \[ x = 10 \]

Thus, the solution to the equation \( 2(4x - 7) = 66 \) is:

\[ \boxed{10} \]

-6(x+7)=18

To solve the equation \(-6(x + 7) = 18\), follow these steps:

Step 1: Distribute the \(-6\)

Distributing \(-6\) gives:

\[ -6x - 42 = 18 \]

Step 2: Add \(42\) to both sides

Next, add \(42\) to both sides of the equation:

\[ -6x - 42 + 42 = 18 + 42 \] \[ -6x = 60 \]

Step 3: Divide both sides by \(-6\)

Now, divide both sides by \(-6\) to solve for \(x\):

\[ x = \frac{60}{-6} \] \[ x = -10 \]

Thus, the solution to the equation \(-6(x + 7) = 18\) is:

\[ \boxed{-10} \]

5n-6(n+3)=14

To solve the equation \( 5n - 6(n + 3) = 14 \), follow these steps:

Step 1: Distribute \(-6\)

Distributing \(-6\) across \((n + 3)\) gives:

\[ 5n - 6n - 18 = 14 \]

Step 2: Combine like terms

Now, combine the \(n\) terms:

\[ (5n - 6n) - 18 = 14 \] \[ -n - 18 = 14 \]

Step 3: Add \(18\) to both sides

Add \(18\) to both sides to isolate \(-n\):

\[ -n = 14 + 18 \] \[ -n = 32 \]

Step 4: Multiply both sides by -1

To solve for \(n\), multiply both sides by \(-1\):

\[ n = -32 \]

Thus, the solution to the equation \( 5n - 6(n + 3) = 14 \) is:

\[ \boxed{-32} \]