190
the sum for 20 + 40 + 70 + 80 = 210
70 + 80 + 70 + 30+ 80 + 80+ 80 = 490
The result of the equation - 130 plus 80 plus 40 plus 80, is found as follows;130 + 80 + 40 + 80= ( 130 + 80 ) + 40 + 80= 210 + ( 40 + 80 )= 210 + 120= 330Answer = 330
The result of the equation - 130 plus 80 plus 60 plus 70, is found as follows;130 + 80 + 60 + 70= ( 130 + 80 ) + 60 + 70= 210 + ( 60 + 70 )= 210 + 130= 340Answer = 340
The result of the equation - 70 plus 90 plus 60 plus 80, is found as follows; 70 + 90 + 60 + 80 = ( 70 + 90 ) + 60 + 80 = 160 + ( 60 + 80 ) = 160 + 140 = 300 Answer = 300
The result of the equation - 130 plus 70 plus 60 plus 80, is found as follows;130 + 70 + 60 + 80= ( 130 + 70 ) + 60 + 80= 200 + ( 60 + 80 )= 200 + 140= 340Answer = 340
40 + 80 = 120
The result of the equation - 130 plus 40 plus 60 plus 80, is found as follows;130 + 40 + 60 + 80= ( 130 + 40 ) + 60 + 80= 170 + ( 60 + 80 )= 170 + 140= 310Answer = 310
The result of the equation - 130 plus 80 plus 60 plus 40, is found as follows;130 + 80 + 60 + 40= ( 130 + 80 ) + 60 + 40= 210 + ( 60 + 40 )= 210 + 100= 310Answer = 310
-40 + 70 = 30
738
80 - 10 = 30 + 40Both sides of the sum now equal 70.