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3 years ago

If x-5(x-7)=-7 then x equals what?

1 answer:

7 0

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simplify x - 5x + 35 to -4x + 35

subtract 35 from both sides

simplify -7 - 35 to -42

divide both sides by -4

two negatives make a positive

simplify 42/4 to 21/2

Answer: x = 21/2.

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Peter's dad is 60, which is four times as old as peter. Write an equation that can be used to find peter's age. Then solve the e

MrRissso [65]

Answer:

Step-by-step explanation:

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3 years ago

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Sal built a card table with a top area of 900 square inches. What is the length, in inches, of one side of the table?

Klio2033 [76]

Answer:
30

Explanation:
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Write an explicit formula for an, the nth term of the sequence 4, -24, 144, ....

nadezda [96]

Answer:

Tn = 4(-6)^n-1

Step-by-step explanation:

Write an explicit formula for an, the nth term of the sequence 4, -24, 144, ....

The sequence is a geometric sequence

Tn = ar^n-1

a is the first term

a = 4

r = -24/4 =144/-24

r = -6

Substitute

Tn = 4(-6)^n-1

3 0

3 years ago

I know that real numbers consist of the natural or counting numbers, whole numbers, integers, rational numbers and irrational nu

ra1l [238]

The imaginary unit $i$ belongs to the set of complex numbers, denoted by $\mathbb C$ . These numbers take the form $a+bi$ , where $a,b$ are any real numbers.

The set of real numbers, $\mathbb R$ , is a subset of $\mathbb C$ , where each number in $\mathbb R$ can be obtained by taking $b=0$ and letting $a$ be any real number.

But any number in $\mathbb C$ with non-zero imaginary part is not a real number. This includes $i$ .

"is it possible that i can use an imaginary number for a real number"

I'm not sure what you mean by this part of your question. It is possible to represent any real number as a complex number, but not a purely imaginary one. All real numbers are complex, but not all complex numbers are real. For example, 2 is real and complex because $2=2+0i$ .

There are some operations that you can carry out on purely imaginary numbers to get a purely real number. A famous example is raising $i$ to the $i$ -th power. Since $i=e^{i\pi/2}$ , we have

$i^i=\left(e^{i\pi/2}\right)^i=e^{i^2\pi/2}=e^{-\pi/2}\approx0.2079$

3 0

3 years ago

last year 1/5 of the students in your class played a sport this year 10 students join the class five of the new students play a

tino4ka555 [31]

Answer:

Step-by-step explanation:

last year 1/5 of the class played sports, so s = (1/5) c

the next year, s increased by 5, c increased by 10 and the fraction changed to 1/4, so for the next year (s+5) = (1/4)(c+10)

To solve this we can substitute s = (1/5)c from the first equation into the second, so

((1/5)c + 5)=(1/4)(c+10), simplify both sides

(1/5)c + 5 = (1/4)c + 10/4, simplify 10/4 to 5/2

(1/5)c + 5 = (1/4)c + 5/2, multiply both sides by 20 to eliminate fractions (least common multiple of 2, 4 and 5)

4c + 100 = 5c + 50, subtract 4c, subtract 50 from both sides

50 = c, number of students in class last year was 50, this year is 10 more, so this year is 60

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3 years ago