Which expression is equivalent to 0.4 − (−0.7)?

Mathematics

1 answer:

Pani-rosa [81]3 years ago

6 0

0.4 + 0.7 because a - and a - equal a plus

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Which is the slope of for(-5,9) and (-5,-5)

BabaBlast [244]

Answer: undefined

Step-by-step explanation:

The answer is undefined because when you plug in the points in the formula

y2-y1/ x2-x1 the denominator is 0 which makes it undefined. Also when you put it into a graphing calculator it will say that its undefined.

6 0

3 years ago

-x-1=5 can somebody answer this fo me THX :)

Nitella [24]

Answer: -6

Step-by-step explanation:

-x-1=5

-x=5+1

-x=6

divide both sides by -1

x=-6

8 0

3 years ago

Read 2 more answers

the half-life of strontium-90 is approximately 29 years. how much of a 500 g sample of strontium-90 will remain after 58 years

Yuliya22 [10]

Answer: 125 g

<u>Step-by-step explanation:</u>

$A = P_o\cdot e^{kt}\\\\\text{First, use the given information to find k:}\\\\\bullet A=\dfrac{1}{2}P_o\\\\\bullet k = unknown\\\\\bullet t=29\text{ years}\\\\\dfrac{1}{2}P_o=P_o\cdot e^{k(29)}\\\\\\\dfrac{1}{2}=e^{k(29)}\qquad divided\ both\ sides\ by\ P_o\\\\\\ln\bigg(\dfrac{1}{2}\bigg)=ln\bigg(e^{k(29)}\bigg)\qquad applied\ ln\ to\ both\ sides\\\\\\ln\bigg(\dfrac{1}{2}\bigg)=29k\qquad simplified-ln\ and\ e\ cancel\ out\\\\\\\dfrac{ln\bigg(\dfrac{1}{2}\bigg)}{29}=k\qquad divided\ 29\ from\ both\ sides\\\\\\-0.0239=k$

$\text{Now, use the following in the equation to solve for A:}\\\\\bullet A=unknown\\\bullet P_o=500\\\bullet k=-0.0239\\\bullet t=58\text{ years}\\\\A=500\cdot e^{(-0.0239)(58)}\\\\.\quad=500\cdot e^{-1.386}\\\\.\quad=125$