The simplest form of -(6x+2y)+4(2x-y) = -2(-x+3y).
567,890
+567,096
________
1,134,986
V=lw*h/3
So since its a square l and w are the same
11*11 = 121
h=20
20/3= 6.6666666
V=121*6.6666666
V= 806.66667
It says to estimate first 1,537 turns to 2,000 because the 5 is 5 or more so the 1 becomes 2 and everything else is zeros. Now multiply 2000x 242=484,000 is the Estimation. Now find the correct product for 1,537x242=371,954