Prove that 3(x+1)(x+7)-(2x+5)² is never positive

Mathematics

2 answers:

scZoUnD [109]2 years ago

3 0

Step-by-step explanation:

3(x + 1)(x + 7) − (2x + 5)²

3(x² + 8x + 7) − (4x² + 20x + 25)

3x² + 24x + 21 − 4x² − 20x − 25

-x² + 4x − 4

-(x² − 4x + 4)

-(x − 2)²

A squared number is never negative (provided x is a real number), so -(x − 2)² is never positive.

Reika [66]2 years ago

3 0

Answer:

-27x - 219

Step-by-step explanation:

3x+3 * 3x+21 - 6x+15

9x+6 - (6x+15 * 6x+15)

9x+6 - 36x+325

-27x - 219

You might be interested in

10. The area of a square frame is 55 square inches. Find the length of one side of the

Amanda [17]

Answer:

see explanation

Step-by-step explanation:

The area (A) of a square is calculated as

A = s² ( s is the side length )

Given A = 55 , then

s² = 55 ( take the square root of both sides )

s = $\sqrt{55}$ ≈ 7 in ( to the nearest whole inch )

s ≈ 7.4 in ( to the nearest tenth of an inch )

6 0

2 years ago

Read 2 more answers

I need help? if someone could please help me that would be awesome.

Andre45 [30]

Answer:

35 millimeters

Step-by-step explanation:

1.4 inches * 1millimeters / 0.04inches = 35 millimeters

use this equation:

starting units * desired units / starting units = desired units

3 0

3 years ago

Read 2 more answers

If a school bought 3 cheese pizzas and 1 pepperoni pizza how many cheese and pepperonis pizzas did they get if they bought 6 che

oksian1 [2.3K]

$\text{Hello there!}\\\\\text{Turn this into a ratio:}\\\\\text{For everyone 3 cheese pizzas, they get 1 pepperoni pizza}\\\\\text{The ratio would be 3:1}\\\\\text{We need to find how many pepperoni pizzas they got if they bought 6}\\\text{cheese pizzas}\\\\\text{3 times 2 makes 6, so multiply 1 times to get your answer}\\\\\text{The ratio would be 6:2}\\\\\boxed{\text{2 pepperoni pizzas (8 pizzas in total)}}$