Answer:
x=10/c
Step-by-step explanation:
3(cx-7)=9
(cx-7)=3
cx=10
x=10/c
Group like terms then
add like terms
d-2d-10+7=8-10+d
-d-3=-2+d
add d to both sides
-3=-2+2d
add 2 to both sides
-1=2d
divide both sides by 2
-1/2=d
I divided 315 by any random number and chose the one that gave me a whole number
So I got

x
Answer:
4 years old
Step-by-step explanation:
His sister is x years old.
Gary is 1 year less than 3 times her age, so his age is
3x - 1
His age is 11, so we can write an equation.
3x - 1 = 11
Add 1 to both sides.
3x = 12
Divide both sides by 3.
x = 4
Answer: She is 4 years old.
The cost of one roll of plain wrapping paper is $8 and one roll of holiday wrapping paper is $14.
Step-by-step explanation:
Let,
Cost of one plain wrapping paper = x
Cost of one holiday wrapping paper = y
According to given statement;
6x+y=62 Eqn 1
3x+10y=164 Eqn 2
Multiplying Eqn 2 by 2

Subtracting Eqn 1 from Eqn 3

Dividing both sides by 19

Putting y = 14 in Eqn 1

Dividing both sides by 6

The cost of one roll of plain wrapping paper is $8 and one roll of holiday wrapping paper is $14.
Keywords: linear equation, elimination method
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