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4 years ago

The solution to #68 and #70

Mathematics

1 answer:

atroni [7]4 years ago

8 0

The trick is to write appropriate equations and then solve the system of equations you've created.

"sum of two numbers is -5:" x + y = -5

"difference is -1:" x-y = -1

Add these two equations together. This will cause y to drop out, and you will be left with an equation in x alone:

2x = - 6, so x = -3. Subst. -3 for x in either equation, above, and find the corresponding y value.

Then write your solution as (-3, y ) (write in your value for y).

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Which expression is equivalent to -15x + 5?

salantis [7]

Answer:

the answer is a b c or d

Step-by-step explanation:

because I'm smart

6 0

3 years ago

A ballplayer catches a ball 3.4s after throwing it vertically upward. with what speed did he throw it, and what height did it re

Daniel [21]

From the equation of motion, we know,

$s=ut+\frac{1}{2}at^{2}$

Where s= displacement

u= initial velocity

a= gravitational force

t= time

Displacement is 0 since the ball comes back to the same point from where it was thrown.

A = $-9.8m/s^{2}$ since the ball is thrown upwards.

Plug the known values into the equation.

=> $0=u\left ( 3.4 \right )+\frac{1}{2}\left ( -9.81 \right )(3.4^{2})$

Solving for u gives :

u= 16.67 m/ sec ....... equation (1)

At maximum height, final velocity i.e v is 0

Time take to reach the top = $\frac{3.4}{2} = 1.7 sec$

$v^{2}=u^{2}+2as$

=> $0=(16.67)^{2}+2(-9.81)(s)$

Solving for s we get

s= 14.16 m

4 0

3 years ago

IM Not too sure on this. can someone please help me out?

DENIUS [597]

All it is asking is to plug the given x values into the equation (which are 0, 2, 4) and see what you get for y.
4y - 2x =16

4y - 2 (0) = 16
4y = 16
y = 4

4y - 2 (2) = 16
4y - 4 = 16
4y = 20
y = 5

4y - 2 (4) = 16
4y - 8 = 16
4y = 24
y = 6

so D

5 0

3 years ago

Factoring stages its hard 4 me plz help hoomans

PolarNik [594]

Answer:

ok so what part

Step-by-step explanation:

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3 years ago

What's the probability of obtaining a 3 digit number at random which is DIVISIBLE by 7

pochemuha

Answer:

32/225 ≈ 0.1422

Step-by-step explanation:

If you consider "3-digit" numbers to be between 100 and 999, inclusive, there are 128 such numbers divisible by 7. The probability of choosing one at random is ...

128/900 = 32/225 = 0.1422...(repeating)

If you consider all non-negative integers less than 1000 to be "3-digit numbers," then the probability is ...

142/1000 = 0.142 (exactly)

6 0

3 years ago