Explanation

Since her salary was increased by 8%, we can set up the equation:

x + 0.08x = 237.60

Combine like terms:

1.08x = 237.60

Divide both sides by 1.08:

x = 237.60 / 1.08

x = 220

So, Ali's weekly salary before the increase was $220.

Explanation

12 - 5x = x + 30

Add 5x to both sides:

12 = 6x + 30

Subtract 30 from both sides:

-18 = 6x

Divide both sides by -6:

x = -18/6

x = -3

So, the value of x is -3.

Explanation

First, find the difference in weight:

160 - 152 = 8 pounds

Then, divide the difference by the original weight:

8 ÷ 160 = 0.05

Convert the decimal to a percentage:

0.05 × 100% = 5%

So, the athlete's weight decreased by 5%.

Explanation

3900 ÷ 500 = 7.8

Explanation

15,873 × 28 = 444,444

Explanation

If 25% of a certain number is 1600, we can set up an equation:

25% of x = 1600

Convert the percentage to a decimal:

0.25x = 1600

Divide both sides by 0.25:

x = 1600 / 0.25

x = 6400

So, the certain number is 6400.

Now, we need to find 10% of 6400:

10% of 6400 = 0.10 x 6400 = 640

Explanation

The series is obtained by multiplying the previous term by a increasing sequence of numbers:

• 2 × 2 = 4
• 4 × 3 = 12
• 12 × 4 = 48
• 48 × 5 = 240
• 240 × 6 = 1440

Explanation

The series is obtained by adding 10, 20, 30, 40, ... to the previous term:

• 50 + 10 = 60
• 60 + 20 = 80
• 80 + 30 = 110
• 110 + 40 = 150
• 150 + 50 = 200

Explanation

The series is obtained by multiplying the previous term by 4:

4 × 4 = 16

16 × 16 = 256

256 × 256 = 65536

Explanation

839 minus 680 equals 159.