Question

[(2×a+178)×15+90]:45 egal 630

Answer 1

[ ( 2*a +178 ) * 15 + 90 ] / 45 = 630
 [ ( 2*a + 178 ) * 15 +90 ] = 630 *45
  ( 2a + 178 ) *15 +90 = 28350
   ( 2a +178 ) *15 = 28350 -90
   30a + 2670 = 28260
   30 a = 28260 -2670
   30a = 25590
   a = 25590 / 30
   a = 853

Answer 2

(30 x a + 2670 + 90) :45= 630
(30 x a + 2760) : 45 = 630
30 x a + 2760 =630 x 45
30 xa + 2760 =28350
30 x a = 28350- 2760
30 xa =25590
a = 25590: 30
a =853