Module 4 Pretest

Mathematics

1 answer:

jekas [21]2 years ago

8 0

5, it’s 24
6. It’s 3:55 am

You might be interested in

Every round in a competition costs 30 diamonds and you get 10 shards. How many diamonds will it cost you to reach 1,024 shards?

Firdavs [7]

Answer:

3,090 diamonds

Step-by-step explanation:

To get 10 shards, you need to spend 30 diamonds.

First thing we need to find, how many rounds you need to play to get 1,024 shards if in each round you win 10 shards?

1,024/10 = 102,4

But you can not play 102.4 rounds, you only can play whole numbers, so we need to round it to the next whole number (not the previous one, because in that case, we would get less than 1,024 shards)

Then you need to play 103 rounds.

And each round costs 30 diamonds, then the total number of diamonds that you need is:

103*30 diamonds = 3,090 diamonds

3 0

2 years ago

Find the sum and product of the roots. 2x^2 + 6x - 8 = 0

netineya [11]

Suppose you can factorize:

$ax^2+bx+c=a(x-r_1)(x-r_2)$

Then by expanding the right side, you have

$ax^2+bx+c=a(x^2-(r_1+r_2)x+r_1r_2)=ax^2-a(r_1+r_2)x+ar_1r_2$

which means in this case, you have to have

$\begin{cases}6=-2(r_1+r_2)\\-8=2r_1r_2\end{cases}\implies\begin{cases}r_1+r_2=-3\\r_1r_2=-4\end{cases}$