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3 years ago

Using factoring by difference of squares to solve the equation 4x^2-81=0.

Mathematics

1 answer:

LuckyWell [14K]3 years ago

5 0

Answer:

Step-by-step explanation:

−

Add

to both sides of the equation.

Divide each term by

and simplify.

Tap for more steps...

Take the square root of both sides of the equation to eliminate the exponent on the left side.

√

The complete solution is the result of both the positive and negative portions of the solution.

Tap for more steps...

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Need this ASAP Having a hard time with the 10 squares 3

e-lub [12.9K]

Answer:

Area= 50√3 units^2

Step-by-step explanation:

Given:

In given triangle, there are two sides with length 10√3 and 20 along with angle of 30° between them.

As the given triangle is SAS triangle, we'll use the following formula to calculate its area:

A=1/2absinC

where a= 20

b= 10√3

and c=30°

Now putting values we get:

A=(1/2)(20)(10√3) sin(30)

=100√3(1/2)

=50√3

so the area is 50√3 units^2 !

4 0

3 years ago

Solve for x. 4x-4< 8 AND 9x +5 > 23 is it a, b,c or d ?

Alex

Answer:

$A)\displaystyle2 < x < 3$

Step-by-step explanation:

A compound inequality is an inequality that combines two simple inequalities

we are given that

$\displaystyle 4x - 4 < 8 \ \: \text{and} \: \: 9x + 5 > 23$

solving x for the first equation:

$\displaystyle 4x - 4 < 8$

add 4 to both sides:

$\displaystyle 4x < 12$

divide both sides by 4 and since we are dividing both sides by a positive number the inequality won't swap

$\displaystyle x < 3$

solving x for the second equation:

$\displaystyle 9x + 5 > 23$

cancel 5 from both sides:

$\displaystyle 9x > 18$

divide both sides by 9 and since we are dividing both sides by a positive number:

$\displaystyle x > 2$

therefore by combining the equations we obtain:

$\displaystyle\boxed{2 < x < 3}$

hence,

our answer is A)

5 0

3 years ago

find the sale price of the item. round to two decimal places if necessary original price $225.60 markdown 80 %

IgorC [24]

Answer:

gan if you could anssbdhe

Step-by-step explanation:

6 0

3 years ago

The value of y varies directly with x. If x = 15, then y = 12. What is the value of y, when x = 21?

Andrei [34K]

Answer: 16.8

Step-by-step explanation: if x= 15 and y =12 we know that y =.8 of x or 4/5 of x. Knowing this we can divide x (21) by 5 and get 4.2. We can then multiply this and get 16.8 which is 4/5 of x(21). y=16.8

8 0

3 years ago

ellie is preheating her oven before using it to bake. the initial temperature of the oven is 65° and the temperature will increa

11111nata11111 [884]

Answer:

The temperature of the oven after 6 minutes is 125 degrees and after 10 minutes its 165 degrees.

Step-by-step explanation:

10 x 6 = 60

60+65=125

10 x 10 = 100

100+65=165

8 0

3 years ago