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

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)