Why do two negatives equal a positive when adding?

1 answer:

4 0

Two negatives do not equal a positive when adding. If you're in debt and you add more debt, does that get you out of debt?

Two negatives do equal a positive when you're multiplying them together though. This makes sense if you imagine multiplication as squishing or stretching a particular number on the number line. For example, imagine multiplying 2 x 1/2 as squishing the number 2 two times closer to 0. When you multiply 2 by a negative number, say, -1, you squish it so far down that you flip it to the negative side of the number line, bringing it to -2. You can imagine a similar thing happening if you multiply a number like -4 by -2. You squish -4 down to zero, and then flip it to the positive side and stretch it by a factor of 2, bringing it to 8.

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If x^(3/5) = 1.84, then x^2 = ? Show Work. A.) 7.63 B.) 10.40 C.) 21.15

svetlana [45]

X^(3/5) = 1.84

x^(3/5) = (1.84)

Raise both sides of the equation to (5/3).

This is so that on the side with x, 3/5 * 5/3 = 1.

(x^3/5 )^5/3 = (1.84)^(5/3)

x^(3/5 * 5/3) = 1.84^(5/3)

x^1 = 1.84^(5/3)

x = 1.84^(5/3)

But remember we are solving for x^2.

x = 1.84^(5/3)

x^2 = (1.84^(5/3))^2

x^2 = 1.84^(5/3 *2 )

x^2 = 1.84^(10/3)

Use a calculator here.

x^2 = 1.84^(10/3) ≈ 7.63

Option A.

Cheers!

5 0

3 years ago

The lengths of pregnancies in a small rural village are normally distributed with a mean of 262 days and a standard deviation of

RideAnS [48]

Answer:

The range in which we can expect to find the middle 68% of most pregnancies is [245 days , 279 days].

Step-by-step explanation:

We are given that the lengths of pregnancies in a small rural village are normally distributed with a mean of 262 days and a standard deviation of 17 days.

Let X = lengths of pregnancies in a small rural village

SO, X ~ Normal( $\mu=262,\sigma^{2} = 17^{2}$ )