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3 years ago

I will never get the hang of these questions help

Mathematics

1 answer:

jeyben [28]3 years ago

4 0

First term is -7, so a_1 = -7

To get the next term, we add on 4. We can see this if we subtract like so
d = (2nd term) - (1st term) = (-3) - (-7) = -3+7 = 4

So d = 4 is the common difference.

Apply a_1 = -7 and d = 4 to get...
a_n = a_1 + d*(n-1)
a_n = -7 + 4*(n-1)
a_n = -7 + (n-1)*4

Answer: Choice A

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Q2. A train travels at a constant speed of 45 m/s. a) Calculate the distance travelled by the train in:

alex41 [277]

Answer:

i) 1350 m

ii) 5400 m

Step-by-step explanation:

<u>Formula for Speed</u>

$\boxed{\sf Speed=\dfrac{Distance}{Time}}$

Rearrange the formula so that Distance is the subject:

$\implies \sf Distance = Speed \times Time$

<h3><u>Question (i)</u></h3>

Given:

Speed = 45 m/s (meters per second)
Time = 30 seconds

Substitute the given values into the formula for distance:

$\implies \sf Distance = 45 \times 30 = 1350\:m$

<h3><u>Question (ii)</u></h3>

Given:

Speed = 45 m/s (meters per second)
Time = 2 minutes

As the time is given in a different unit of time as the speed, we must first convert the time into seconds:

1 minute = 60 seconds

⇒ 2 minutes = 60 × 2 = 120 seconds

Therefore:

Speed = 45 m/s (meters per second)
Time = 120 seconds

Substitute the values into the formula for distance:

$\implies \sf Distance = 45 \times 120 = 5400\:m$

3 0

1 year ago

Read 2 more answers

Factorise the following completely 3ax+2ay+6bx+4by

marissa [1.9K]

Answer:

(a+2b)(3x+2y)

Step-by-step explanation:

3ax+2ay+6bx+4by = a(3x+2y)+2b(3x+2y) = (a+2b)(3x+2y)

4 0

3 years ago

Read 2 more answers

8. Is the following statement true or false? Justify your conclusion. If a and b are nonnegative real numbers and a + b =0, then

atroni [7]

Answer:

If $a + b = 0$ then $a = 0$ and $b =0$

a | b | a + b (answer)

0 | 0 | 0

0 | 1 | 1

0 | 2 | 2

1 | 0 | 1

2 | 0 | 2

1 | 1 | 2

2 | 1 | 3

Step-by-step explanation:

Considering the following conditions for the real numbers:

$a\geq 0\\b\geq 0$

Following the rules of these in-equations, it is possible to deduce:

$a + b \geq 0$

Then, if the proposed statement is:

$a + b = 0$

The conditions above shall comply the requirements established, but first, analyzing the statement:

If $a \geq 0$ and $b \geq 0$ then $a + b \geq a$ , $a + b \geq b$ and $a + b \geq 0$ .

If $a = 0$ and b a non negative real number, then $a + b \geq b$ , but because to $a = 0$ , then $a + b = b$ . Due to the commutative property of sums, the same behavior will be presented if $b = 0$ and a a non negative real number.