A 25-ft ladder leaning against a wall begins to slide. How fast is the top of the ladder sliding down the wall at the instant of time when the bottom of the ladder is 15 ft from the wall and sliding away from the wall at the rate of 4 ft/sec

Speed the top of the ladder is sliding down = 6.7 ft/sec

Step-by-step explanation:

Using equivalent proportion

15 ft 4 ft/sec

25 ftX ft/sec

Hence X = (25 x 4) ÷ 15 = 6.6666667 ≅ 6.7 ft/sec

The answer is 24.

Step-by-step explanation:

Follow PEMDAS (parenthesis, exponents, multiplication, division, addition, subtraction).

Multiplication and Division can be on the same step from left to right, the same applies to Addition and Subtraction.

Original: 7 + 3² + (12 - 8) ÷ 2 x 4

Parenthesis: 7 + 3² + (4) ÷ 2 x 4

Exponents: 7 + 9 + 4 ÷ 2 x 4

Multiplication and Division from left to right: 7 + 9 + 2 x 4 = 7 + 9 + 8

Addition: 7 + 9 + 8 = 24

Hope this helps! :)