Answer:
93
Step-by-step explanation:
Answer: B and C
Step-by-step explanation: For A, vertical angles can be complimentary or supplementary. For D, vertical angles can sometimes be acute but not always.
Answer:
r = 4/5
Step-by-step explanation:
Formula
Sum of an infinite geometric series = a / (1 - r)
Givens
Sum = 5*a
a = a
r = ?
Solution
5a = a/(1 - r) Divide both sides by a
5a/a = a / (a * (1 - r) The a's on the right cancel
5 = 1 / (1 - r) Multiply both sides by 1 - r
5*(1 - r) = 1*(1 - r)/(1 - r) The 1 - r s on the right cancel
5*(1 - r) = 1 Remove the brackets.
5 - 5r = 1 Subtract 5 from both sides
5-5 - 5r = 1 - 5 Combine
-5r = - 4 Divide by - 5
r = 4/5
7-3x=4(2+x)<--Distribute
7-3x=8+4x
-7...... -7
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-3x=1+4x
-4x ....-4x
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-7x=1
/-7 /7
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x=-1/7
