Question

calculati:
a) -15+ (-9) x (-4+5) - (-3-8) x (-7+3)
b) 23-5 x (-9-3) + (7-15) x (-2-4)
c) -4+ (-6-9) x (-9+7) - (5+3-1) x (-4+3)

Answer 1

A) - 15-9-44= - 68
B)23+60+48=131
C) - 4+30+7=33

Answer 2

a ) -15 + ( -9 ) x ( -4 + 5 ) - ( -3 - 8 ) x ( -7 + 3 ) =
= -15 + ( -9 ) x 1 - ( -11 ) x ( -4 )
= -15 + ( -9 ) + 11 x ( -4 ) 
= -15 - 9 - 44
= -24 - 44 
= -68

b ) 23 - 5 x ( -9 - 3 ) + ( 7 - 15 ) x ( -2 - 4 )  =
= 23 - 5 x ( -12 ) - 8  x ( -6 ) 
= 23 + 60  + 48
= 83 + 48
= 131

c ) -4 + ( -6 - 9 ) x ( -9  + 7 ) - ( 5 + 3 - 1 ) x ( -4  + 3 ) = 
= -4 - 15 x ( -2 ) - 7 x ( -1 ) 
= -4 + 30  + 7 
= 26  + 7
= 33