All categories

3 years ago

Why is he wrong? What is the correct answer?

Mathematics

1 answer:

Tems11 [23]3 years ago

4 0

Answer:

Step-by-step explanation:

He had the incorrect slope for the second line, his line has a positive slope of one while the equation has a slope of negative 1.

x+y=1

y=-x+1

He graphed x+1 instead of -x+1

If he graphed them correctly the lines would intersect when the equations were equal

2x+4=-x+1

3x+4=1

3x=-3

x=-1, making y=2x+4 become

y=2(-1)+4

y=2

So the solution was supposed to be the point (-1,2)

You might be interested in

The sum of 28+29+42=99. So what addition property was used Commutative, associative, identity, or distributive ?

IrinaVladis [17]

28 + 29 + 42 = 28 + 42 + 29 = 99

Commutative property: a + b = b + a

3 0

3 years ago

X×9=y, y-70=11 , y=?

solmaris [256]

Answer:

y=81

Step-by-step explanation:

x=9 and y=81

y-70=11 (add 70 onto 11)

y=81

5 0

3 years ago

Read 2 more answers

Find the geometric mean of 8 and 17

maria [59]

Oh gosh oh I thought had the president of the

5 0

3 years ago

Suppose after 2500 years an initial amount of 1000 grams of a radioactive substance has decayed to 75 grams. What is the half-li

krok68 [10]

Answer:

The correct answer is:

Between 600 and 700 years (B)

Step-by-step explanation:

At a constant decay rate, the half-life of a radioactive substance is the time taken for the substance to decay to half of its original mass. The formula for radioactive exponential decay is given by:

$A(t) = A_0 e^{(kt)}\\where:\\A(t) = Amount\ left\ at\ time\ (t) = 75\ grams\\A_0 = initial\ amount = 1000\ grams\\k = decay\ constant\\t = time\ of\ decay = 2500\ years$

First, let us calculate the decay constant (k)

$75 = 1000 e^{(k2500)}\\dividing\ both\ sides\ by\ 1000\\0.075 = e^{(2500k)}\\taking\ natural\ logarithm\ of\ both\ sides\\In 0.075 = In (e^{2500k})\\In 0.075 = 2500k\\k = \frac{In0.075}{2500}\\ k = \frac{-2.5903}{2500} \\k = - 0.001036$

Next, let us calculate the half-life as follows:

$\frac{1}{2} A_0 = A_0 e^{(-0.001036t)}\\Dividing\ both\ sides\ by\ A_0\\ \frac{1}{2} = e^{-0.001036t}\\taking\ natural\ logarithm\ of\ both\ sides\\In(0.5) = In (e^{-0.001036t})\\-0.6931 = -0.001036t\\t = \frac{-0.6931}{-0.001036} \\t = 669.02 years\\\therefore t\frac{1}{2} \approx 669\ years$

Therefore the half-life is between 600 and 700 years

5 0

3 years ago

Please help

Drupady [299]

Answer:

56°

Step-by-step explanation:

2x+3x+5=90

5x=90-5

5x=85

x=85÷5

x=17

m<2=3x+5=3(17)+5=51+5=56

3 0

3 years ago