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2 years ago

The equation x2 – 1x – 90 = 0 has solutions {a, b}. What is a + b

2 answers:

8 0

X^2 - x - 90 =0
This equation is in standard form ax^2+ bx + c
The sum of the solutions is -b/a (a and b are the coefficients from the equation above, not the solutions to the equation)
The answer is 1/1 = 1

REY [17]2 years ago

3 0

Answer:

Step-by-step explanation:

Alright, let get started.

The given equation is : $x^2-1x-90=0$

This is a quadratic equation.

The standard form of a quadratic equation is : $AX^2+BX+C=0$

Comparing the given equation with standard one, the values of A ,B and C are :

A is 1

B is -1

C is -90

Since a and b are the roots of the equation, so the formula for sum of roots a+b will be = $\frac{-B}{A}$

a+b= $-\frac{-1}{1} =1$

hence a+b will be 1 : Answer

Hope it will help :)

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Mike took clothes to the cleaners three times last month. First, brought 4 shirts and of slacks and paid $11.45. Then brought

GenaCL600 [577]

Complete Question:

Mike took clothes to the cleaners three times last month. First, brought 4 shirts and 1 pair of slacks and paid $11.45. Then brought 7 shirts, 2 pairs of slacks, and 2 sports and paid $35.39. Finally, brought 5 shirts and 2 sports and paid $21.43 . How much was charged for each shirt, each pair of slacks, and each sports coat?

Answer:

The charges

For each Shirt = $1.49

For each pair of slacks = $5.49

For each sports coat = $6.99

Step-by-step explanation:

Let Shirt = a

Let pair of slacks = b

Let sports coat = c

First, brought 4 shirts and 1 pair of slacks and paid $11.45

= 4a + b = 11.45 ..........Equation 1

b = 11.45 - 4a

Then brought 7 shirts, 2 pairs of slacks, and 2 sports and paid $35.39

= 7a + 2b + 2c = 35.39.........Equation 2

5 shirts and 2 sports and paid $21.43

5a + 2c = 21.43............Equation 3

Hence:

4a + b = 11.45 ..........Equation 1

7a + 2b + 2c = 35.39.........Equation 2

Using elimination method

Multiply Equation 2 by the coefficient of b = 1 in Equation 1

Multiply Equation 1 by the coefficient of b = 2 in Equation 2

8a + 2b = 22.9 .......Equation 4

7a + 2b + 2c = 35.39.........Equation 2

Subtracting Equation 2 from Equation 4

= a - 2c = -12.49 ........Equation 5

a = -12.49 + 2c

Subtituting -12.49 + 2c for a in Equation 3

5a + 2c = 21.43............Equation 3

5(-12.49 + 2c) + 2c = 21.43

= -62.45 + 10c + 2c = 21.43

Collecting like terms

10c + 2c = 21.43 + 62.45

12c = 83.88

c = 83.88/12

c = 6.99

5a + 2c = 21.43............Equation 3

Substituting 6.99 for c in Equation 3

5a + 2(6.99) = 21.43

5a + 13.98 = 21.43

5a = 21.43 - 13.98

5a = 7.45

a = 7.45/5

a = 1.49

4a + b = 11.45 ..........Equation 1

Substituting 1.49 for a in Equation 1

4(1.49) + b = 11.45

b = 11.45 - 4(1.49)

b = 11.45 - 5.96

b = 5.49

Therefore, since the charges

For each shirt = a

The charges for each Shirt = $1.49

For each pair of slacks = b

The charges for each pair of slacks = $5.49

For each sports coat = c

The charges for each sports coat = $6.99

3 0

2 years ago

Tristan is an administrator for a private nonprofit college and read a surprising statistic that 74% of graduates from private n

STatiana [176]

Answer: $H_0: p=0.74\\\\ H_a:p$

Step-by-step explanation:

Let p be the population proportion for the graduates from private nonprofit colleges in the region had at least one outstanding student loan at the time of graduation.

Given : Tristan is an administrator for a private nonprofit college and read a surprising statistic that 74% of graduates from private nonprofit colleges in the region had at least one outstanding student loan at the time of graduation.

i.e. $p=0.74$

He believes that percentage is high and claims that the proportion of graduates at his college is less than the regional rate.

i.e. $p$

Since, the null hypothesis is a statement which always takes equal sign or generally shows " no difference " where as alternative hypothesis takes unequal signs.

Then, the null and alternative hypotheses for this hypothesis test :-

$H_0: p=0.74\\\\ H_a:p$

6 0

2 years ago

B(1)=16 <br> b(n)=b(n-1)+1 <br> Find the second term in the sequence

anyanavicka [17]

Answer:

Step-by-step explanation:

b(n)=b(n-1)+1 means a term can be found by taking it's previous term and adding 1 to it.

So if b(1)=16, the next term b(2)=16+1=17.

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3 years ago

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What is the answer to 2×[4×(2+1)×3] And how did you get it

ira [324]

Answer is 72

Step by step

Using order of math rules of PEMDAS, we do the inner parentheses “P” first, working outwards with parentheses and then exponents, multiply and divide, add and subtract.

2x [4x(2+1)x3] add inner parentheses

2 x [4 x 3 x 3] multiply inside brackets

2 x 36 multiply for your answer

= 72

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9 months ago

How do I solve this? Will mark brainliest, just trying to learn.

GaryK [48]

Answer:

Step-by-step explanation:

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3 years ago

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