Thực hiện phép tính :
\(a)215+\left(-38\right)-\left(-58\right)-15=177-\left(-73\right)\)
\(=250\)
\(b)5.\left(-3\right)^2-14.\left(-8\right)+\left(-40\right)=45-\left(-112\right)+\left(-40\right)\)
\(=117\)
a) 215 + ( -38) - ( -58) - 15
= 215 - 38 + 58 - 15
= ( 58 - 38 ) + ( 215 - 15)
= 20 + 200 = 220
b) 5. (-3)2 - 14. ( -8) + ( -40)
= 5. 9 - 14. (-8) + ( -40)
= 45 - ( -112 ) + (-40)
= 45 + 112 - 40
= 45 - 40 + 112
= 5 + 112
