bonjour
A = - ( - a /b) - ( b / - c )
A = - ( 90 / - 10 ) - ( - 10 / - 5 )
A = - ( - 90/10 ) - ( 10/5)
A = 90/10 - 20/10 = 70/10 = 7
B = b² - 4 x a x c
B = ( - 10 )² - 4 ( - 90 * 5 )
B = 100 - 4 ( - 450 )
B = 100 + 1 800 = 1 900
C = - c² - a : b x c
C = ( - 5 )² - ( - 90 : - 10 ) x 5
C = 25 - ( 9 ) x 5
C = 25 - 45
C = - 20
