This may be a bad question but is negative 7 still a prime number?

NARA [144]

What kinda of math is this so i can answer..

:)

5 0

3 years ago

I have 8 pennies and some quarters, nickels, and dimes. The number of pennies plus nickels equals the number of dimes. I have 3

Darina [25.2K]

There are five nickels.

Let w = the number of pennies; x = the number of nickels; y = the number of dimes; z = the number of quarters.

Then, we have three equations with four unknowns:

(1) w + x = y

(2) 3w = 2z

(3) 2y = 3z

However, there is a fourth unstated condition: w, x, y, and z must all be integers.

Assume that z = 6 (to avoid fractions).

From Equation (2), w = 4.

From Equation (3), y = 9.

Insert the values for w and y into equation (1).

4 + x = 9

x = 9 – 4 = 5

Thus, there are 4 pennies, 5 nickels, 9 dimes, and 6 quarters.

Check: 4 pennies + 5 nickels = 9 dimes

6 quarters + 4 pennies = 3 quarters for every 2 pennies

9 dimes + 6 quarters = 3 dimes for every 2 quarters

5 0

3 years ago

Read 2 more answers

2x squared + 9x=-5 i need to solve for x

In-s [12.5K]

$2x^2+ 9x=-5 \\ \\2x^2 + 9x+5 =0 \\\\a=2, \ \ b=9 , \ \ c=5 \\\\\Delta =b^2-4ac = 9^2 -4\cdot 2\cdot 5 = 81-40=41 \\ \\x_{1}=\frac{-b-\sqrt{\Delta} }{2a}=\frac{-9-\sqrt{41}}{2\cdot 2 }=\frac{-9-\sqrt{41}}{ 4 }\\\\ x_{2}=\frac{-b+\sqrt{\Delta} }{2a}=\frac{-9+\sqrt{41}}{2\cdot 2 }=\frac{-9+\sqrt{41}}{4 }$

3 0

3 years ago

What graph represents the piecewise function?

adoni [48]

Answer: Lower left corner

A piecewise function is basically a combination of other functions to make one single function. We can break up the given piecewise function into two parts:

f(x) = x-4

OR

f(x) = -2x

The f(x) will change depending on what x happens to be. If x is 0 or smaller, then we go with f(x) = x-4. Otherwise, if x is larger than 0, then we opt for f(x) = -2x.

To graph this, we basically graph y = x-4 and y = -2x together on the same coordinate system. We only graph y = x-4 if x is 0 or smaller. Likewise, we graph y = -2x when x > 0. This results in the graph shown in the lower left corner of your four answer choices.

Note: the closed circle means "include this point as part of the graph". The open circle means "exclude this point as part of the graph". So this is why the upper right corner is very close but not quite the answer we want.

5 0

3 years ago

Do I need to put parentheses in this? Why it why not?

Oksana_A [137]

Answer:

Parentheses can change the result of the answer. If you want to add 4 and 0.95 first, then multiply that number by 3, then you need parentheses.

Step-by-step explanation:

When you are given the question 3 X 4 + 0.95, it has to types of operations. People solve using the order PEDMAS:

Parentheses,

Exponents,

Division and Multiplication,

Addition and Subtraction.

Since there are no parentheses or exponents, the solver will do multiplication first, then addition.

3 X 4 + 0.95 Multiply first

= 12 + 0.95 Now add

= 12.95 Answer without parentheses

If you add parentheses around 4 + 0.95, the answer would change. According to PEDMAS, the parentheses must be solved before anything else.

3 X (4 + 0.95) Add inside parentheses

= 3 X (4.95) Now multiply

= 14.85 Answer with parentheses

If you added parentheses around 3 X 4, the answer would not change, because you still multiply first.

(3 X 4) + 0.95 Solving parentheses first

= 12 + 0.95 Add

= 12.95 Answer same as original

3 0

3 years ago