Question

[(15*6-10*3*a)*4+15*4]*10=30*100

Answer 1

[ ( 15 * 6 - 10 * 3 * a ) * 4 + 15 * 4 ] * 10 = 30 * 100
[ ( 90 - 30 * a ) * 4 + 60 ] * 10 = 3,000
( 90 - 30 * a ) * 4 + 60 = 3,000 ÷ 10
( 90 - 30 * a ) * 4 + 60 = 300
( 90 - 30 * a ) * 4 = 300 - 60
( 90 - 30 * a ) * 4 = 240
90 - 30 * a = 240 ÷ 4
90 - 30 * a =60
30 * a = 90 - 60
30 * a = 30
a = 30 ÷ 30
a = 1