Jawabanmu

2014-09-10T17:19:16+07:00
(1/2xA)-25=425
(1/2xA) = 450
A = 450 x 2
A= 900
2014-09-10T17:26:14+07:00
..... kita misalkan n
(1/2 X n)-25 = 25x17
1/2n-25 = 25 X17
1/2 n = 25X17+25
1/2n = 425 + 25
1/2 n = 450
n = 450 : 1/2
n = 900