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3 years ago

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Mathematics

2 answers:

Semenov [28]3 years ago

8 0

Okay okay okay

Answer:

r = $\frac{30}{71}$

Step-by-step explanation:

12 - $\frac{r}{6}$ = 5

6 × 12 × r × 6 - $\frac{r}{6}$ = 5 × 6

72r - r = 30

71r = 30

r = 30 ÷ 71

r = $\frac{30}{71}$

____ [38]3 years ago

5 0

Answer:

r=30/71

Step-by-step explanation:

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How to find the area of a polygon

ipn [44]

The rectangle is 7 x 4 so the area is 28 sq cm
The triangle has a base of 4 and a height of 3.
The formula is A = 1/2 * b*h
You have 2 triangles so:
2(1/2)*4*3= 12 sq cm
Add together:
28 + 12= 40 sq cm

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3 years ago

What is the best method to be use in solving quadratic equation x²+16x+63=0?

Strike441 [17]

Answer:

Factorization

Step-by-step explanation:

This can be easily factorized into (x+7)(x+9)=0 which can be solved for the two roots x = -7 and x = -9

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4 years ago

What is 3,200,000,000,000 in scientific notation

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3 years ago

Let $f(x) = 2x^2 + 3x - 9,$ $g(x) = 5x + 11,$ and $h(x) = -3x^2 + 1.$ Find $f(x) - g(x) + h(x).$

Viefleur [7K]

QUESTION 1

Given that:

$f(x)=2x^2+3x-9$ ,

$g(x)=5x+11$ ,

and

$h(x)=-3x^2+1$

Then;

$f(x)-g(x)+h(x)=2x^2+3x-9-(5x+11)+(-3x^2+1)$

$f(x)-g(x)+h(x)=2x^2+3x-9-5x-11-3x^2+1$

Group similar terms;

$f(x)-g(x)+h(x)=2x^2-3x^2+3x-5x-11-9+1$

Simplify;

$f(x)-g(x)+h(x)=-x^2-2x-19$

QUESTION 2

Given that;

$f(x)=4x-7$ .

$g(x)=(x+1)^2$

and

$s(x)=f(x)+g(x)$

Substitute the functions;

$s(x)=4x-7+(x+1)^2$

Substitute x=3

$s(3)=4(3)-7+(3+1)^2$

$s(3)=12-7+(4)^2$

$s(3)=5+16$

$s(3)=21$

QUESTION 3

Given:

$f(x)=3x+2$

$g(x)=x^2-5x-1$

$f(g(x))=f(x^2-5x-1)$

This implies that;

$f(g(x))=3(x^2-5x-1)+2$

Expand the parenthesis;

$f(g(x))=3x^2-15x-3+2$

$f(g(x))=3x^2-15x-1$

QUESTION 4

The given function is;

$f(x)=3(x-6)^2+1$

Let

$y=3(x-6)^2+1$

$\Rightarrow y-1=3(x-6)^2$

$\Rightarrow \frac{y-1}{3}=(x-6)^2$

$\Rightarrow \sqrt{\frac{y-1}{3}}=x-6$

$\Rightarrow x=6+\sqrt{\frac{y-1}{3}}$

The range is:

$\frac{y-1}{3}\ge0$

$y-1\ge0$

$y\ge1$

The interval notation is;

$[1,+\infty)$

6 0

4 years ago

Consider the following pair of equations:

V125BC [204]

The pair of equations:
y = x + 4
y = -2x - 2

To solve the system of equation by substitution, you would substitute one variable for it's equivalent expression. Combining the pair of equations into one equation in only one variable. The easiest way to do this is by substituting out the variable y because it is already alone on one side of the equal sign. Substitute the y in the second equation for: x+4

x+4 = -2x - 2
solve for x
x + 2x = -2 -4
3x = -6
x = -2

now use the value for x to find y by putting into either equation.

y = x + 4
y = (-2) + 4
y = 2

solution is: (-2, 2)

4 0

3 years ago