Speedometer 18693

The Macháček family went on a 3-day trip to Třeboň. They didn't want to get too tired but wanted to see a lot. Therefore, they drove at a walking pace, and at the end of the 3rd day, they measured 90 km on the speedometer. On the second day, they traveled three times as much as on the first day, and on the third day, they traveled 22 km less than on the second day.

Correct answer:

a =  16
b =  48
c =  26

Step-by-step explanation:

a+b+c=90
b=3a
c=b-22

a+b+c=90
b=3·a
c=b-22

a+b+c = 90
3a-b = 0
b-c = 22

Pivot: Row 1 ↔ Row 2
3a-b = 0
a+b+c = 90
b-c = 22

Row 2 - 1/3 · Row 1 → Row 2
3a-b = 0
1.333b+c = 90
b-c = 22

Row 3 - 1/1.33333333 · Row 2 → Row 3
3a-b = 0
1.333b+c = 90
-1.75c = -45.5


c = -45.5/-1.75 = 26
b = 90-c/1.33333333 = 90-26/1.33333333 = 48
a = 0+b/3 = 0+48/3 = 16

a = 16
b = 48
c = 26

Our linear equations calculator calculates it.

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