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3 years ago

Please complete z2+9z-90=(z-6)(z+?) ...?

Mathematics

2 answers:

Pachacha [2.7K]3 years ago

8 0

Answer:

Answer would be 15.

Step-by-step explanation:

We have to complete the expression given as

$z^{2}+9z-90=(z-6)(z+?))$

We will try to factorize the expression given in the left side.

$z^{2}+9z-90=z^{2}+15z-6z-90$

= z(z+15)-6(z-15)

= $(z-6)(z-15)$

Now we will compare this factorized form with the right side of the expression.

(z-6) (z-15) (= (z-6) (z+?)

We find question mark is 15.

Therefore, the answer is 15.

notka56 [123]3 years ago

4 0

The answer is: (z - 6)(z + 15)

z² + 9z - 90 = z*z + 15z - 6z - 6*15 =
= (z*z + 15z) - (6z + 6*15) =
= z(z + 15) - 6(z + 15) =
= (z - 6)(z + 15)

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Katen [24]

$\green{\large\underline{\sf{Solution-}}}$

Given expression is 

$\rm :\longmapsto\:\dfrac{5 \times {25}^{n + 1} - 25 \times {5}^{2n} }{5 \times {5}^{2n + 3} - {25}^{n + 1} }$

can be rewritten as

$\rm \: = \: \dfrac{5 \times { {(5}^{2} )}^{n + 1} - {5}^{2} \times {5}^{2n} }{5 \times {5}^{2n + 3} - {( {5}^{2} )}^{n + 1} }$

We know,

$\purple{\rm :\longmapsto\:\boxed{\tt{ {( {x}^{m} )}^{n} \: = \: {x}^{mn}}}} \\$

And

$\purple{\rm :\longmapsto\:\boxed{\tt{ \: \: {x}^{m} \times {x}^{n} = {x}^{m + n} \: }}} \\$

So, using this identity, we

$\rm \: = \: \dfrac{5 \times {5}^{2n + 2} - {5}^{2n + 2} }{{5}^{2n + 3 + 1} - {5}^{2n + 2} }$

$\rm \: = \: \dfrac{{5}^{2n + 2 + 1} - {5}^{2n + 2} }{{5}^{2n + 4} - {5}^{2n + 2} }$

can be further rewritten as

$\rm \: = \: \dfrac{{5}^{2n + 2 + 1} - {5}^{2n + 2} }{{5}^{2n + 2 + 2} - {5}^{2n + 2} }$

$\rm \: = \: \dfrac{ {5}^{2n + 2} (5 - 1)}{ {5}^{2n + 2} ( {5}^{2} - 1)}$

$\rm \: = \: \dfrac{4}{25 - 1}$

$\rm \: = \: \dfrac{4}{24}$

$\rm \: = \: \dfrac{1}{6}$

Hence, 

$\rm :\longmapsto\:\boxed{\tt{ \dfrac{5 \times {25}^{n + 1} - 25 \times {5}^{2n} }{5 \times {5}^{2n + 3} - {25}^{n + 1} } = \frac{1}{6} }}$

4 0

3 years ago

You guys are Smart, Answer me this. But I need It fast-

miss Akunina [59]

Answer:

E = 58

F = 32

G = 90

Step-by-step explanation:

3x + 31 + 5x -13 + 90 = 180

3x + 31 + 5x -13 = 90

8x = 90 - 31 + 13

8x = 72

x = 72 / 8

x = 9

E = 3(9) + 31 = 27+31 = 58

F = 5(9)-13 = 45 - 13 = 32

G = 90

8 0

2 years ago

Select all radical expressions that are equivalent to 5 2/3

dsp73

Answer:

is it to tell you tht everything means nothing if i cant have you

Step-by-step explanation:

is it too late to tell you that everythign means nothing if i cant have talk is it wronghald you dtrings ooo keeping my distance knoow feeling

4 0

3 years ago

2t + t =68 a. find t b. fint 2t

balandron [24]

Answer:

t = 22 $\frac{2}{3}$

2t = 45 $\frac{1}{3}$

Step-by-step explanation:

3t = 68

t = 68/3

4 0

3 years ago

You are fundraising for the schools track team by selling clothing. The first day, you sell 13 t-shirts and 17 pairs of shorts f

Anastasy [175]

Answers:

one t-shirt costs $10

one pair of shorts costs $15

============================================================

Explanation:

x = cost of one t-shirt

y = cost of one pair of shorts

13x+17y = 385 is the first equation because 13x represents the money you get from selling 13 shirts, and the 17y represents the amount you get from selling 17 shorts. The total 13x+17y is given to be $385

The second equation is 13x+12y = 310 for similar reasoning, but this time you sell 12 shorts this time and you get $310 in revenue.

The system of equations we have is:

$\begin{cases}13x+17y = 385\\13x+12y=310\end{cases}$

There are a few ways to solve this system. Possibly the quickest method is to note that the 13x shows up twice, so we can subtract straight down to eliminate the x terms

So,

13x-13x becomes 0x or just 0, and the x terms go away.
17y-12y becomes 5y
385-310 becomes 75

After those three subtractions, we have the equation 5y = 75 which solves to y = 15 after dividing both sides by 5. This means the cost of one pair of shorts is $15

Plug this y value into any equation involving x and y, and solve for x

13x+17y = 385

13x+17(15) = 385

13x+255 = 385

13x = 385-255

13x = 130

x = 130/13

x = 10

Therefore, each t-shirt costs $10

-----------------

To help verify the answer, plug (x,y) = (10,15) into each equation. We should end up with a true result after simplifying both sides.

Start with the first equation

13x+17y = 385

13(10)+17(15) = 385

130+255 = 385

385 = 385

We get a true result which confirms the first equation.

Repeat for the second equation.

13x+12y = 310

13(10)+12(15) = 310

130+180 = 310

310 = 310

Both equations are true so (x,y) = (10, 15) has been fully confirmed.

6 0

3 years ago