If 55\(_x\) + 52\(_x\) = 77\(_{10}\) find X
A
5
B
6
C
7
D
10
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
5 \(\times\) x\(^1\) + 5 \(\times\) x\(^0\) + 5 \(\times\) x\(^1\) + 2 \(\times\) x\(^0\) = 77
(change all to base 10)
5x + 5 + 5x + 2 = 77
10x + 7 = 77
10x = 77-7
10x = 70
x = 70/10
x = 7
Source: Myschool Past Questions Archive (Record #9304)