$(a+b)^2=a^2+2ab+b^2\qquad(*)\\\\-------------------------------\\\\x^2+6x-16=0\qquad\text{add 16 to both sides}\\\\x^2+6x=16\\\\x^2+2(x)(3)=16\qquad\text{add}\ 3^2\ \text{to both sides}\\\\\underbrace{x^2+2(x)(3)+3^2}_{(*)}=16+3^2\\\\(x+3)^2=16+9\\\\(x+3)^2=25\Rightarrow x+3=\pm\sqrt{25}\\\\x+3=-5\ \vee\ x+3=5\qquad\text{subtract 3 from both sides}\\\\\boxed{x=-8\ \vee\ x=2}$

3 0

4 years ago

Shawna took a test that had a total of 20 items. She got 4/5 of the items correct. How many items did she get correct?

ehidna [41]

Shawna got 16 items correct

Step-by-step explanation:

To find the percentage of answers or part of total answers we multiply the fraction with the total number of items.

Given

Total items on test = 20

Correct items fraction = 4/5

Then,

$Correct\ items=\total\ items * \fraction\ of\ correct\ answers\\= 20 * \frac{4}{5}\\=\frac{80}{5}\\=16$

Shawna got 16 items correct

Keywords: Percentage, fractions

Learn more about fractions at:

#LearnwithBrainly

4 0

4 years ago

Help help help help help help help

sdas [7]

It would be 120.

Look at the first column, 40. It’s basically multiplication and you can just use a calculator.

For example, 40 x 1 = 40,
And if you looks the second column, it’s being multiplied by 2. Which would be 40 x 2, you just have to multiply 3 x 40 which is 120.

Sorry for my english

7 0

3 years ago

Is plant propagation applicable in your locality?why or why not?​

Is plant propagation applicable in your locality?why or why not?