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All triangles have the same value, and all circles have the same value. What is the sum of two circles?

 

$\Delta + \bigcirc + \Delta + \bigcirc + \Delta + \bigcirc + \Delta = 21$

$\bigcirc + \Delta+\bigcirc+\Delta+\bigcirc + \Delta + \bigcirc = 16$

$\bigcirc + \bigcirc = \ \, ?$

 Jul 28, 2021
 #1
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4T + 3C = 21

3T + 4C = 16

 

Multiply the fist one by 3 and the second one by 4

 

12T+9C=63

12T+16C=64

 

Subtract the first one FROM the second one

7C = 1

C = 1/7

2C=2/7

 

check

4T+3/7 = 21

4T = 20 +4/7

T= 5 and 1/7

Put into the second equation

3*(5+1/7)+ 4(1/7)

=15+3/7 + 4/7

=16

 

Works perfectly.

 Jul 28, 2021

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