All categories

3 years ago

Find the sum 12x^2+9x^2

1 answer:

5 0

Let's simplify step-by-step.
12x^2+9x^2
Combine Like Terms:
=12x^2+9x^2
=(12x^2+9x^2)
=21x^2

You might be interested in

HELP!!! PLEASE!!!!

Makovka662 [10]

Answer:

y = 2x² - 5x + 7

Step-by-step explanation:

For this problem, imagine the standard form, which is:

f(x) = ax² + bx + c = y

Using the table, and adding that y at the end, we can plug in and write out the following equations. (Writing it out is important):

f(-1) = a(-1)² + b(-1) + c = 14

f(0) = a(0)² + b(0) + c = 7

f(1) = a(1)² + b(1) + c = 4

f(2) = a(2)² + b(2) + c = 5

Now if this doesn't look familiar, it's actually a systems of equations using the a, b, and c elements as your three variables! If you simplify the equations:

f(-1) = a - b + c = 14

f(0) = c = 7

f(1) = a + b + c = 4

f(2) = 4a + 2b + c = 5

Something unique just happened. We have already defined what ' c ' is!

c = 7

Setting that aside, if you remove the f(x) portion of the equations, you're left with:

a - b + c = 14

a + b + c = 4

4a + 2b + c = 5

Using the two upper equations, if we add them together (you can do that as it doesn't change the values of the variables) you get:

2a + 2c = 18

Note: the ' b ' variables cancelled out in the addition [ b + (-b) ]

If you further simplify the equation:

a + c = 9

Awesome. Now we already know that c = 7, so if you plug that into the equation:

a + 7 = 9

Solve for a. So then a = 2

Now that we know the following:

a = 2

c = 7

We can then use the equation:

a + b + c = 4

And solve for b!

2 + b + 7 = 4

Simplify.

b + 9 = 4

Simplify.

b = -5

Now at this point, since you know what a, b and c are, you can write the equation!

f(x) = 2x² - 5x + 7

You can confirm your work by putting any of the x values in the table through!

4 0

3 years ago

Read 2 more answers

4x+7y=19 y=x+9 substitution method

Ugo [173]

Answer:

Point Form: (-4,5)

Equation Form: x=-4,y=5

Step-by-step explanation:

Please give me brainiest!!!

3 0

3 years ago

9/20

Stella [2.4K]

Question:

Find the number of real number solutions for the equation. x^2 + 5x + 7 = 0

Answer:

The number of real solutions for the equation $x^{2}+5 x+7=0$ is zero

Solution:

For a Quadratic Equation of form : $a x^{2}+b x+c=0$ ---- eqn 1

The solution is $x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$

Now , the given Quadratic Equation is $x^{2}+5 x+7=0$ ---- eqn 2

On comparing Equation (1) and Equation(2), we get

a = 1 , b = 5 and c = 7

In $x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}$ , $b^2 - 4ac$ is called the discriminant of the quadratic equation

Its value determines the nature of roots

Now, here are the rules with discriminants:

1) D > 0; there are 2 real solutions in the equation

2) D = 0; there is 1 real solution in the equation

3) D < 0; there are no real solutions in the equation

Now let solve for given equation

$D= b^2 - 4ac\\\\D = 5^2 - 4(1)(7)\\\\D = 25 - 28 \\\\D = -3$

Since -3 is less than 0, this means that there are 0 real solutions in this equation.

4 0

3 years ago

Cara and shirley, working together, can clean the house in 66 hours. working alone, shirley takes three times as long as cara. h

iVinArrow [24]

Assuming that they both work at the same pace together 66/2=33*3=99 to get the whole house done because she takes 3 times as long and has to pick up the slack when cara is gone i think at least it sounds logical in my mind but maybe somebody thinks different but final answer
t=99 hours

7 0

3 years ago

How to find the area

WARRIOR [948]

L + W
length plus width

example: L = 10" W = 20" 10 x 20 = 200

6 0

2 years ago