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anygoal [31]
1 year ago
13

What is a21 of the arithmetic sequence for which a7 = -19 and a10 =-28

Mathematics
1 answer:
AlekseyPX1 year ago
3 0

a_{n} = a_{1} + (n - 1)d \\ a_{7} = a_{1} + (7 - 1)d \\ a_{7} = a_{1} + 6d \\ a_{10} = a_{1} + 9d

- 19 = a_{1}  + 6d \\  - 28 =  a_{1} + 9d \\  \\  - 19 =  a_{1} + 6d \\ 28 =  -  a_{1} - 9d \\\  - 3d = 9 \\ d =  - 3

a_{1} =  - 19 - 6d =  - 19 - 6( - 3) =  - 1 \\

a_{21} =  a_{1} + (21 - 1)d \\ a_{21} =  - 1 + 20( - 3) =  - 61

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Solve 4X^2+7 = 8X +4 by using the quadratic formula
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Answer:

(1.5,0)

(.5,0)

Step-by-step explanation:

Quadratic formula below

We first need to move everything to one side of the equation

4x²-8x+3=0

Then plug everything in

(8±√(-8²-4*4*3))/(2*4)

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To calculate the ± we need to do when where it's adding and then negative

we have

(8+4)/8=3/2

and hten

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4 0
3 years ago
Solve.<br> 4 - 2x = 10<br> A)-7<br> B)-3<br> C)0<br> D)3
mars1129 [50]

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4 0
3 years ago
The soccer field is 105 meters long. The football field is 120 yards long. Which is longer?
ASHA 777 [7]

The football field is longer than soccer field.

<h3>What is a expression? What is a mathematical equation? What is unit conversion?</h3>

A mathematical expression is made up of terms (constants and variables) separated by mathematical operators. A mathematical equation is used to equate two expressions. Equation modelling is the process of writing a mathematical verbal expression in the form of a mathematical expression for correct analysis, observations and results of the given problem. Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.

We have a soccer field that is 105 meters long and a football field is 120 yards long.

In one yard, we have -

1 yard = 0.9144 meters

Then, in 120 yards, we will have -

120 x 0.9144 = 109.728 meters

Now, 109.728 meters > 105 meters.

Therefore, the football field is longer than soccer field.

To solve more questions on dimensions and unit conversion, visit the link below -

brainly.com/question/4613077

#SPJ1

8 0
1 year ago
A triangle with an angle measuring 104° must be which of these?
Tema [17]
This will be an obtuse angled triangle because one angle is greater than 90 degrees.
8 0
3 years ago
Terry had 400 inches of ribbon before he cut pieces of ribbon that were 8 inches long how many 15 inch pieces can terry cut fro
Nikitich [7]
This could be wrong but the remaining pieces he can cut is 3 because if you divide 400 with 8 , it’s 35 as the answer, so then subtract 35 with 15 till you can subtract 15 from it
4 0
2 years ago
Read 2 more answers
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