All categories

4 years ago

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

Mathematics

2 answers:

lina2011 [118]4 years ago

8 0

Answer:

Value of a+b is:

Step-by-step explanation:

For a equation

Ax²+Bx+C=0

if {a,b} are its solutions or equation has roots a and b

Then, sum of roots= -B/A and product of roots=C/A

i.e. a+b= -B/A and ab=C/A

Here, the equation is:

x² – x – 90 = 0

i.e. A=1,B= -1 and C= -90

then, a+b= -(-1)/1

i.e. a+b=1

Hence, value of a+b is:

ololo11 [35]4 years ago

4 0

It can be factorised as
$(x - 10)(x + 9)$
so the solutions are
x= 10 and x = -9

so the sum of the solutions is 10 -9 which is 1

You might be interested in

What is -2 = 5 / (2x+3)

LUCKY_DIMON [66]

Answer:

x = -11/4

Step-by-step explanation:

Given that:

-2 = 5 / (2x+3)

Multiplying both sides by (2x + 3)

-2(2x + 3) = 5

"-" sign will alter the inner signs

-4x -6 = 5

Adding 6 on both sides:

-4x -6 +6 = 5 + 6

-4x = 11

Dividing both sides by -4

-4x/-4 = 11/-4

x = -11/4

i hope it will help you!

3 0

3 years ago

A loss of $500 in stock market is worse than a gain of 200 in the stock market

Serhud [2]

Yes, that's a true statement. Losing money is worse than gaining it.

8 0

3 years ago

Can someone please help me with my maths

Korvikt [17]

Answer:

Step-by-step explanation:

Recall that the "point-slope" form of a linear equation may be expressed as

y = mx + b,

where m is the gradient.

If m is negative, the gradient is negative.

If m is positive, the gradient is positive.

In our case, if we consider option A,

x + 3y = -2 (rearranging)

3y = -x -2

y = (-1/3) x - (2/3)

if we compare this to the general equation at the top, we can see that

gradient, = m = (-1/3) which is negative.

hence option a has a negative gradient.

3 0

3 years ago

Read 2 more answers

2. Find the general relation of the equation cos3A+cos5A=0

mars1129 [50]

<h2>Answer:</h2>

$A=\frac{\pi}{8}+\frac{n\pi}{4}or\ A=\frac{\pi}{2}+n\pi$

<h2>Step-by-step explanation:</h2>

<h3>Find angles</h3>

$cos3A+cos5A=0$

________________________________________________________

<h3>Transform the expression using the sum-to-product formula</h3>

$2cos(\frac{3A+5A}{2})cos(\frac{3A-5A}{2})=0$

________________________________________________________

<h3>Combine like terms</h3>

$2cos(\frac{8A}{2})cos(\frac{3A-5A}{2})=0\\\\ 2cos(\frac{8A}{2})cos(\frac{-2A}{2})=0$

________________________________________________________

<h3>Divide both sides of the equation by the coefficient of variable</h3>

$cos(\frac{8A}{2})cos(\frac{-2A}{2})=0$

________________________________________________________

<h3>Apply zero product property that at least one factor is zero</h3>

$cos(\frac{8A}{2})=0\ or\ cos(\frac{-2A}{2})=0$

________________________________________________________

<h3>Cross out the common factor</h3>

$cos\ 4A=0$

________________________________________________________

<h3>Solve the trigonometric equation to find a particular solution</h3>

$4A=\frac{\pi}{2}or\ 4A=\frac{3\pi}{2}$

________________________________________________________

<h3>Solve the trigonometric equation to find a general solution</h3>

$4A=\frac{\pi}{2}+2n\pi \ or\\ \\ 4A=\frac{3 \pi}{2}+2n \pi\\ \\A=\frac{\pi}{8}+\frac{n \pi}{4\\}$

________________________________________________________

<h3>Reduce the fraction</h3>

$cos(-A)=0$

________________________________________________________

<h3>Simplify the expression using the symmetry of trigonometric function</h3>

$cosA=0$

________________________________________________________

<h3>Solve the trigonometric equation to find a particular solution</h3>

$A=\frac{\pi }{2}\ or\ A=\frac{3 \pi}{2}$

________________________________________________________

<h3>Solve the trigonometric equation to find a general solution</h3>

$A=\frac{\pi}{2}+2n\pi\ or\ A=\frac{3\pi}{2}+2n\pi,n\in\ Z$

________________________________________________________

<h3>Find the union of solution sets</h3>

$A=\frac{\pi}{2}+n\pi$

________________________________________________________

<h3>Find the union of solution sets</h3>

$A=\frac{\pi}{8}+\frac{n\pi}{4}\ or\ A=\frac{\pi}{2}+n\pi ,n\in Z$

<em>I hope this helps you</em>

5 0

2 years ago

Someone please explain with an answer and explaination please!!!

Yanka [14]

Answer:

1
-6

Step-by-step explanation:

<em>Refer to attached</em>

f(-2) = 1
f(x) = -1 ⇒ x = -6

Finding the required coordinate is shown on the graph

8 0

3 years ago