2x²+12x-7 =0 (completing the square) give your answer to 2 decimal places

Subtract and simplify. Show work please!

ra1l [238]

1) Final expression: $+7y^2-6y-17$

2) Final expression: $21x^3-46x^2+59x-30$

Step-by-step explanation:

1)

The first expression is

$(-2y^2-11y-7)-(-9y^2-5y+10)$

First, we remove the 2nd bracket by changing the sign of all the terms inside:

$-2y^2-11y-7-+9y^2+5y-10$

Now we group the terms with same degree together:

$(-2y^2+9y^2)+(-11y+5y)+(-7-10)$

Now we solve the expression in each brackets:

$(-2y^2+9y^2)+(-11y+5y)+(-7-10)=\\+7y^2-6y-17$

So, this is the final expression.

2)

The second expression is

$(7x-6)(3x^2-4x+5)$

We apply the distributive property, so we rewrite the expression as follows:

$(7x-6)(3x^2-4x+5)=7x(3x^2-4x+5)-6(3x^2-4x+5)$

Solving both brackets,

$7x(3x^2-4x+5)-6(3x^2-4x+5)=\\21x^3-28x^2+35x-18x^2+24x-30$

Now we group terms of same degree together:

$21x^3-28x^2+35x-18x^2+24x-30=\\21x^3+(-28x^2-18x^2)+(35x+24x)-30$

And solving each bracket,

$21x^3+(-28x^2-18x^2)+(35x+24x)-30=\\21x^3-46x^2+59x-30$

So, this is the final expression.

Learn how to simplify expressions:

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#LearnwithBrainly

3 0

2 years ago

EASY MATH<br> Find all the zeros of f(x)= x^3 − 6x^2 + 13x − 20 given that 1−2i is a zero.<br> x=

Oduvanchick [21]

Answer:

there is only one zero

Step-by-step explanation: and if it easy why you didint do it just ascking

3 0

2 years ago

Find the area of the region bounded by the y-axis, the line y=6, and the line y = 1/2.

Ghella [55]

Solution:

As region bounded by y-axis, the line y=6, and the line y=1/2 is a line segment of definite length on y-axis.

We consider a line , one dimensional if it's thickness is negligible.

So, Line is two dimensional if it's thickness is not negligible becomes a quadrilateral.

So, Area (region bounded by y-axis, the line y=6, and the line y=1/2 is a line segment of definite length on y-axis)= Area of line segment between [,y=6 and y=1/2.]= 6-1/2=11/2 units if we consider thickness of line as negligible.

4 0

2 years ago

The height h in feet of a ball thrown vertically upward from the top of a 288-foot tall building is given by h=288+48t-16t^2 whe

mr Goodwill [35]

6 sec can take penny to strike the ground.

Solution:

Given data:

$H_0=288$ feet

$V_0=48$ feet

$h(t)=288+48t-16t^2$

Re-arrange the terms from greatest degree to smallest degree.

$h(t)=-16t^2+48t+288$

We can solve it by applying quadratic formula,

$$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Here a = –16, b = 48, c = 288

$$t=\frac{-48\pm \sqrt{48^2-4(-16)(288)}}{2(-16)}$

$$t=\frac{-48\pm \sqrt{2304+18432}}{-32}$

$$t=\frac{-48\pm \sqrt{20736}}{-32}$

$$t=\frac{-48\pm144}{-32}$

Now, write find two t's using plus and minus operation.

$$t=\frac{-48+144}{-32},\ \ t=\frac{-48-144}{-32}$

$$t=\frac{96}{-32},\ \ t=\frac{-192}{-32}$

t = –3 (or) t = 6

We cannot write time is negative. so neglect t = –3.

Therefore t = 6.

Hence 6 sec can take penny to strike the ground.

8 0

2 years ago

Mia wants to purchase a pair of jeans. The first time she saw the jeans, they were priced at $36. When she goes back to make the

jasenka [17]

Answer: D

Step-by-step explanation:

1. Subtract 36 to 28.80

2. Divide the answer to the first price (36.00)- 7.5 divided by 36.00 or 36

3. When you calculate and find the answer as a decimal, then make it into a percentage

So if... you divide 7.5 divided by 36, you get the decimal of 0.2, and when you move the decimals two places only, you get your answer of 20%.

Hopefully it helped you!. Have a good day :-).

8 0

2 years ago