11. Solve by completing the square.
- 10x = 5x^2-1

x = (√6/√5) - 1

Step-by-step explanation:

- 10 x = 5x^2 -1

can be written as

5x² + 10x - 1 = 0

completing the square method :

for quadratic equation of the format ax² + bx + c = 0 ,

step 1, divide equation by a

therefore. dividing the equation by 5

=> x² + 2x - (1/5) = 0

=> x² + 2x = 1/5

c - 2b/4 = -1/5 - (2(2)/4) = -(6/5)

b/2 = 1

=> x² + 2x +1 = 6/5

=> (x + 1)² = 6/5

=> x = (√6/√5) - 1

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!