Solve the equation 2x2+8x -1 = 0
by completing the square.
Give your answers correct to 2 decimal places.

x ≈ - 4.12 , x ≈ 0.12

Step-by-step explanation:

2x² + 8x - 1 = 0 ( add 1 to both sides )

2x² + 8x = 1 ( factor out 2 from the first two terms )

2(x² + 4x) = 1

To complete the square

add/ subtract ( half the coefficient of the x- term )² to x² + 4x

2(x² + 2(2)x + 4 - 4) = 1

2(x + 2)² - 8 = 1 ( add 8 to both sides )

2(x + 2)² = 9 ( divide both sides by 2 )

(x + 2)² = ( take square root of both sides )

x + 2 = ± = ± ( subtract 2 from both sides )

x = - 2 ±

Then

x = - 2 - ≈ - 4.12 ( to 2 dec. places )

x = - 2 + ≈ 0.12 ( to 2 dec. places )

Cost of 7 gallons=$24.50

Cost of 1 gallon=24.50/7=3.5

Cost of 15 gallons=15*3.5=52.5

Cost of 15 gallons will be $52.5

The total nom of  code that can be used is equal to 5+3 = 8

For every 8 cars there are 7 trucks

Therefore,

Cars:Truck=8:7

Answer is B)8:7

F=ma

where F=force

m=mass

a=acceleration

Here,

F=4300

a=3.3m/s2

m=F/a

    =4300/3.3

    =1303.03kg

The answer is in the image 

The answer is in the image 

Here,

tip=18%of $32

tip=(18/100)*32

=0.18*32

=$5.76

Total payment=32+5.76=$37.76

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.