Multiply top equation by -2, then add equations so b drops out....solve for a...plug in a to get b
Answer:
n= 4
Step-by-step explanation:
3 multiplied by n is 3n.
3 multiplied by -5 is -15.
so 3n-15= 7-2(n+1)
7-2(n+1) is -2 multiplied by n is -2n and -2 multiplied by 1 is -2.
3n-15=7-2n-2
then move the variables to one side and numbers to the one side.
3n+2n=15+7-2
*If you are moving across the equation the symbols change. Like negative to positive. Division to multiplication.
so 5n=22-2
5n=20
5 multiplied by 4 is 20 so n is going to be 4.
N=4
<h3>
Answer: C) 2.47 cm</h3>
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Explanation:
We have 81 cm^3 of clay. Divide this among the 20 students and each gets 81/20 = 4.05 cm^3 of clay
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The volume of a cone is
V = (1/3)*pi*r^2*h
Solving for h gets us
3V = pi*r^2*h
(3V)/(pi*r^2) = h
h = (3V)/(pi*r^2)
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The diameter is 2.5 cm which cuts in half to 1.25 cm, so this is the radius.
We'll plug this radius in, along with V = 4.05 and pi = 3.14
h = (3V)/(pi*r^2)
h = (3*4.05)/(3.14*(1.25)^2)
h = 2.4764
This value is approximate. Rounding down to the nearest hundredth gets us 2.47
We round down because rounding up to 2.48 will lead to a volume larger than 4.05
Is "ab" an angle? If so, can you try to repost the picture because I cannot see anything so it's hard to try and help you.