Mathematics, 18.03.2021 02:00 missdaisy789

Simplify and verify the results for $( {7x}^{3} + {8x}^{2} - 3)( {x}^{2} - 5) \: \: \: x = 5$
I need step by step explanation

Answers: 1

Show answers

Answers

Answer from: lanakay2006

21440

Step-by-step explanation:

Simplify:(7x³ + 8x² - 3)(x² - 5)

Start by multiplying 7x³ by x² and -5.

7x⁵ - 35x³ + (8x² - 3)(x² - 5)

Multiply 8x² by x² and -5.

7x⁵ - 35x³ + 8x⁴ - 40x² + (-3)(x² - 5)

Multiply -3 by x² and -5.

7x⁵ - 35x³ + 8x⁴ - 40x² -3x² + 15

Combine like terms together.

7x⁵ - 35x³ + 8x⁴ - 43x² + 15

Rearrange the terms in descending power order.

7x⁵ + 8x⁴ - 35x³ - 43x² + 15 Verify (I):

Substitute x = 5 into the above polynomial.

7(5)⁵ + 8(5)⁴ - 35(5)³ - 43(5)² + 15

Evaluate the exponents first.

7(3125) + 8(625) - 35(125) - 43(25) + 15

Multiply the terms together.

21875 + 5000 - 4375 - 1075 + 15

Combine the terms together.

21440

This is the answer when substituting x = 5 into the simplified expression.

Verify (II):

Substitute x = 5 into the expression.

[7(5)³ + 8(5)² - 3][(5)² - 5]

Evaluate the exponents first.

[7(125) + 8(25) - 3][(25) - 5]

Multiply the terms in the first bracket next.

[875 + 200 - 3][25 - 5]

Evaluate the expressions inside the brackets.

[1072][20]

Multiply these two terms together.

21440

This is the answer when substituting x = 5 into the original (unsimplified) expression.

Answer from: sk9600930

21440

Step-by-step explanation:

Simplify:

(7x³ + 8x² - 3)(x² - 5)

Start by multiplying 7x³ by x² and -5.

7x⁵ - 35x³ + (8x² - 3)(x² - 5)

Multiply 8x² by x² and -5.

7x⁵ - 35x³ + 8x⁴ - 40x² + (-3)(x² - 5)

Multiply -3 by x² and -5.

7x⁵ - 35x³ + 8x⁴ - 40x² -3x² + 15

Combine like terms together.

7x⁵ - 35x³ + 8x⁴ - 43x² + 15

Rearrange the terms in descending power order.

7x⁵ + 8x⁴ - 35x³ - 43x² + 15

Verify (I):

Substitute x = 5 into the above polynomial.

7(5)⁵ + 8(5)⁴ - 35(5)³ - 43(5)² + 15

Evaluate the exponents first.

7(3125) + 8(625) - 35(125) - 43(25) + 15

Multiply the terms together.

21875 + 5000 - 4375 - 1075 + 15

Combine the terms together.

21440

This is the answer when substituting x = 5 into the simplified expression.

Verify (II):

Substitute x = 5 into the expression.

[7(5)³ + 8(5)² - 3][(5)² - 5]

Evaluate the exponents first.

[7(125) + 8(25) - 3][(25) - 5]

Multiply the terms in the first bracket next.

[875 + 200 - 3][25 - 5]

Evaluate the expressions inside the brackets.

[1072][20]

Multiply these two terms together.

21440

This is the answer when substituting x = 5 into the original (unsimplified) expression.

Answer from: Quest

add an image

step-by-step explanation:

Answer from: Quest

40 minutes

step-by-step explanation:

add the time and multiply by 2

Other questions on the subject: Mathematics

Mathematics, 21.06.2019 20:00, lexhoangg

Frank owns a $141,000 home, for which he has a 30-year mortgage in the amount of $700 a month. once he has paid off mortgage, how much will he have paid in investment? a. $111,000 b. $109,000 c. $120,000 d. $141,000

Answers: 1

continue

Mathematics, 21.06.2019 20:30, Travisbennington

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.

Answers: 1

continue

Mathematics, 21.06.2019 21:30, lainnn974

Questions 7-8. use the following table to answer. year 2006 2007 2008 2009 2010 2011 2012 2013 cpi 201.6 207.342 215.303 214.537 218.056 224.939 229.594 232.957 7. suppose you bought a house in 2006 for $120,000. use the table above to calculate the 2013 value adjusted for inflation. (round to the nearest whole number) 8. suppose you bought a house in 2013 for $90,000. use the table above to calculate the 2006 value adjusted for inflation. (round to the nearest whole number)

Answers: 3

continue

Mathematics, 21.06.2019 22:10, BilliePaul95

Ellen makes and sells bookmarks. she graphs the number of bookmarks sold compared to the total money earned. why is the rate of change for the function graphed to the left?

Answers: 1

continue

You know the right answer?

Simplify and verify the results for
I need step by step explanation...