Because, if 6 + 6 = 12, then in 6 + 7, 7 can be splitted into 6 + 6 + 1, and so you find it easier...!!
1) Use the distributive property to eliminate parentheses.
.. 3(6x) -3(5) -7(3x) -7(10) = 0
.. 18x -15 -21x -70 = 0 . . . . . . finish multiplying terms
.. -3x -85 = 0 . . . . . . . . . . . . . collect like terms
.. -85 = 3x . . . . . . . . . . . . . . . .add 3x
.. -85/3 = x . . . . . . . . . . . . . . .divide by 3
.. -28 1/3 = x . . . . . . . . . . . . . write as mixed number
2) 5 -(6 +9x) = 9 -(4x -1)
.. 5 -6 -9x = 9 -4x +1 . . . . . eliminate parentheses using the distributive property
.. -1 -9x = 10 -4x . . . . . . . . . collect like terms
.. -1 = 10 +5x . . . . . . . . . . . . add 9x
.. -11 = 5x . . . . . . . . . . . . . . . subtract 10
.. -11/5 = x . . . . . . . . . . . . . . divide by 5
.. -2 1/5 = x . . . . . . . . . . . . . write as mixed number
1) C(2
2) A(-4
3) B(4+(2+1)=4+2)+1
4) D(3(2x4)=(3x2)4
5) A(5+6=6+5
6) C(12x1=1x12
7) D(Exponents
8) A(addition and subtraction
9) A(55
10) B(19
Since giving you the exact answer wouldn't help you learn anything, read this:
to find average get all of the values (98,111,106) and add them up. then do the sum of 98+111+106 divided by total number if values (3)
