There are 187 nickels and 66 dimes in the jar.
Step-by-step explanation:
Given,
Total coins = 253
Value of coins = $15.95 = 15.95*100 = 1595 cents
Value of each nickel = 5 cents
Value of each dime = 10 cents
According to given statement;
x+y=253 Eqn 1
5x+10y=1595 Eqn 2
Multiplying Eqn 1 by 5

Subtracting Eqn 3 from Eqn 2

Dividing both sides by 5

Putting y=66 in Eqn 1

There are 187 nickels and 66 dimes in the jar.
Keywords: linear equation, elimination method
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3n+2n+4=9n+12
5n+4=9n+12
4-12=9n-5n
-8=4n
Divide both sides by 4
n=-2
Answer:
6 kg
Step-by-step explanation:
Given is weight of an object directly varies with the mass of the object .
Let the constant of proportionality be k
So,
Weight = K×(mass of the object)
For an object , weight = 45 N
mass = 9 kg
So , 45 = K×9
K = 5.
Now, for the other object ,
Weight = 30 N. K = 5 (as obtained above)
So, 30 = 5×(mass of the object)
mass of the object = 6 kg.
We have 1.2 × 10^(-4) x 6.25 × 10^(-5 ) = 7,5 x 10^(-9) = 75 x 10^(-10) square kilometers.