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3 years ago

Evaluate 2a - 3b for a = 7 and b = -2. 20 9 8

Mathematics

1 answer:

strojnjashka [21]3 years ago

3 0

2(7) - 3(-2.2098)
14 - (-6.6294)
14 + 6.6294
20.6294

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Pls help (kinda easy)

3241004551 [841]

Answer:

$f(x)=(2x+1)(2x-1)$ .

Step-by-step explanation:

We want to convert the function into the form that let's us easily find the x-intercept, and it would be for the form $(ax+b)(cx+d)$ because then we can find the x-intercept in the following manner:

$(ax+b)(cx+d)=0$

$x=-b/a$

$x=-d/c$

We factor our function $f(x)=4x^2-1$ and get

$\boxed{f(x)=(2x+1)(2x-1)}$

Now this form let's us easily find the x-intercepts:

$x=-1/2$

$x=1/2$

and so we pick the second choice: f(x)=(2x+1)(2x-1).

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3 years ago

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What are the different causes of extinction

givi [52]

Answer:

Step-by-step explanation:

There are five major causes of extinction: habitat loss, an introduced species, pollution, population growth, and overconsumption.

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3 years ago

Anna, Laura and David earn the same monthly salary,

Sonja [21]

Answer:

David saves the most (20%)

Step-by-step explanation:

The fraction Anna saves is given as 19%.

The fraction Laura saves is 1-(17/20) = 3/20 = 15/100 = 15%.

The fraction David saves is 2/(2+8) = 2/10 = 20/100 = 20%.

David saves the most of his salary each month.

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2 years ago

(1-sin^2x) (1+tan^2x)=1

Sphinxa [80]

$\tt (1 - sin ^2x)\times(1+tan^2x) = 1$

L.H.S

$\tt cos^2x \times sec^2x$

$\tt cos^2x \times \frac{1}{cos^2x}$

$\tt \cancel{ cos^2x} \times\cancel{ \frac{1}{cos^2x}}$

$\tt 1$

R.H.S

Hence proved

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2 years ago

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The figure below shows a large rectangle with a small rectangle cut out of it.

Alex Ar [27]

Answer:

40 square units

Step-by-step explanation:

The question gives that both the large shape and the small missing shape are rectangles. The formula for the area of a rectangle is $A=bh$ where "A" is the "Area", "b" is the "base" (bottom edge), and "h" is the height (side edge).

For rectangles, opposite sides (example: top & bottom) have the same length, so the top of the missing rectangle must also be 3.

To find the area of the figure, we must find the difference (subtraction) between the large rectangle (without a hole out of it) and the rectangular hole.

$A_{\text{figure}}=A_{\text{large rectangle without hole}}-A_{\text{hole}}\\A_{\text{figure}}=(7)(7)-(3)(3)\\A_{\text{figure}}=49-9\\A_{\text{figure}}=40$

So, the area of the figure is 40 square units.

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2 years ago

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