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3 years ago

Solve the system of equations by substitution. x+y=18 y=8x

Mathematics

2 answers:

stira [4]3 years ago

4 0

Answer:

Step-by-step explanation:

x + y = 18

y = 8x

x + 8x = 18

9x = 18

x = 18÷9

x = 2

Naddika [18.5K]3 years ago

3 0

Answer:

x=2, y=16

Step-by-step explanation:

x+y=18

y=8x

x+8x=18

x=2

y=16

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What’s is the domain of f(x) ?

marusya05 [52]

Answer:

Step-by-step explanation:

The inputs are -1, 0, 1 and 2. This set represents the domain of the function.

4 0

3 years ago

It cost 5 dollars for a child ticket and 8 dollars for a adult ticket. Total tickets sold were 110 bringing in 820 dollars? How

omeli [17]

Number of child tickets bought is 20

<h3>Solution:</h3>

Given that It cost 5 dollars for a child ticket and 8 dollars for a adult ticket

cost of each child ticket = 5 dollars

cost of each adult ticket = 8 dollars

Let "c" be the number of child tickets bought

Let "a" be the number of adult tickets bought

Total tickets sold were 110 bringing in 820 dollars

Number of child tickets bought + number of adult tickets bought = 110

c + a = 110 ----- eqn 1

Also we can frame a equation as:

Number of child tickets bought x cost of each child ticket + number of adult tickets bought x cost of each adult ticket = 820

$c \times 5 + a \times 8 = 820$

5c + 8a = 820 -------- eqn 2

Let us solve eqn 1 and eqn 2 to find values of "c" and "a"

From eqn 1,

a = 110 - c ------ eqn 3

Substitute eqn 3 in eqn 2

5c + 8(110 - c) = 820

5c + 880 - 8c = 820

-3c = - 60

c = 20

Therefore from eqn 3,

a = 110 - 20 = 90

a = 90

Therefore number of child tickets bought is 20

8 0

3 years ago

Olsjsissjshsjsjsjsh help

stellarik [79]

Answer:

If u really struggle with maths u could use an application names photomath cuz it really helped me. Sry I can't help but I think photomath will be helpful

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3 years ago

The sum of a rational number and an even integer is rational. A) Always True B) Sometimes True C) Usually True D) Never True

SOVA2 [1]

I think that the sum will always be a rational number
let's prove that

any rational number can be represented as a/b where a and b are integers and b≠0

and an integer is the counting numbers plus their negatives and 0
so like -4,-3,-2,-1,0,1,2,3,4....

so, 2 rational numbers can be represented as

a/b and c/d (where a,b,c,d are all integers and b≠0 and d≠0)

their sum is
a/b+c/d=
ad/bd+bc/bd=
(ad+bc)/bd

1. the numerator and denominator will be integers
2. that the denominator does not equal 0

alright
1.
we started with that they are all integers
ab+bc=?
if we multiply any 2 integers, we get an integer
like 3*4=12 or -3*4=-12 or -3*-4=12, etc.
even 0*4=0, that's an integer
the sum of any 2 integers is an integer
like 4+3=7, 3+(-4)=-1, 3+0=3, etc.
so we have established that the numerator is an integer

now the denominator
that is just a product of 2 integers so it is an integer

2. we originally defined that b≠0 and d≠0 so we're good

therefore, the sum of any 2 rational numbers will always be a rational number is the correct answer.

6 0

3 years ago

Last year, a person wrote 126 checks. Let the random variable x represent the number of checks he wrote in one day, and assume

Arisa [49]

Answer: The mean number of checks written per day $=0.3452$