(1/2×……)-25=25×7 berapakah hasilnya

(1/2 x a ) – 25 = 25 x 7
(1/2 x a ) – 25 = 175
(1/2 x a )       = 175 + 25
1/2 x a           = 200
a = 200 : 1/2
a = 200 x 2
a = 400
maka masukkan a kedalam titk2 (1/2 x 400) – 25 = 25 x 7