4a + 7 = please help me
1 answer:
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Answer:
21
Step-by-step explanation:
Let x represent the number of dimes and y represent the number of nickels. The total number of coins is 37; this gives us the equation
x+y = 37
Each dime is worth ten cents, or 0.10, and each nickel is worth five cents, or 0.05. The total amount of money is given by
0.10x+0.05y = 2.65
This gives us the system
To solve this, we will use substitution. We will isolate x in the first equation:
x+y=37
Subtract y from each side:
x+y-y = 37-y
x = 37-y
Substitute this into the second equation:
0.10(37-y)+0.05y = 2.65
Using the distributive property,
0.10(37)-0.10(y)+0.05y = 2.65
3.70-0.10y+0.05y = 2.65
Combining like terms,
3.70-0.05y = 2.65
Subtract 3.70 from each side,
3.70-0.05y-3.70 = 2.65-3.70
-0.05y = -1.05
Divide both sides by -0.05:
-0.05y/-0.05 = -1.05/-0.05
y = 21
There were 21 nickels.
Answer:
Step-by-step explanation:
The equation of the line in Slope-Intercept form is:
Where "m" is the slope and "b" is the y-intercept.
You need to find slope of the line with the formula:
Pick to points of the given line. You can choose the point (60,3) and the point (30,2).
Then, substituting into the formula:
You can observe in the graph that the line intercepts the y-axis at the point (0,1), therefore "b" is:
Substituting the slope and the y-intercept found into , you get the equation of this line:
Where "y" represents the Height (1,000 ft) and "x" represents the Time in seconds.