The right answer is Option A.
Step-by-step explanation:
Let,
x be the postcards
y be the large envelops
According to given statement;
14x+5y=12 Eqn 1
10x+15y=24.80 Eqn 2
Multiplying Eqn 1 by 3;

Subtracting Eqn 2 from Eqn 3;

Dividing both sides by 32

Putting x=0.35 in Eqn 1;

Dividing both sides by 5

Therefore, one large envelope costs $1.42
The right answer is Option A.
Keywords: linear equations, subtraction
Learn more about linear equations at:
#LearnwithBrainly
Answer:
y = 3/5 x+3
Step-by-step explanation:
two points on the graph
(-5,0) (0,3)
the y intercept is 3 (this is where it crosses the y axis)
the slope is
change in y 0 to 3 up 3
------------------ = -------------- = ------- = 3/5
change in x -5 to 0 right 5
we can tell the slope is positive because it goes from bottom left to top right
a negative slope goes from top left to bottom right
slope intercept form is
y=mx+b
y = 3/5 x+3
Answer: Slope = 5/4
y-intercept = 2
Step-by-step explanation:
We have the table:
Months, m Plant height in inches, n
0 2
2 4.5
4 7
6 9.5
We want a linear relationship to represent this table.
A linear relationship can be written as:
y = a*x + b
where a is the slope and b is the y-axis intercept.
For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:
a = (y2 - y1)/(x2 - x1).
In this case we can select any pair of points, for example, i will choose the first two:
(0, 2) and (2, 4.5)
Then the slope is:
a = (4.5 - 2)/(2 - 0) = (2.5/2) = 1.25 = 5/4
Then our line can be written as:
y = (5/4)*x + b
To find the value of b, we can replace the values of any of the points in the equation, for example, i will use the point (0, 2) or x = 0, y = 2.
2 = (5/4)*0 + b
2 = b
Then our equation is:
y = (5/4)*x + 2.
Slope = 5/4
y-intercept = 2
10% of what is 9...
0.10x = 9
x = 9/0.10
x = 90.....he has 90 all together