Given that 1 + 2 + 3 +... 31 + 32 + 33 = 17 * 33, calculate the value of 1-3 + 2-6 + 3-9 + 4-12 +... + 31-93 + 32-96 + 33-99

Given that 1 + 2 + 3 +... 31 + 32 + 33 = 17 * 33, calculate the value of 1-3 + 2-6 + 3-9 + 4-12 +... + 31-93 + 32-96 + 33-99

1-3+2-6+3-9+4-12+...+31-93+32-96+33-99
=(1+2+3+...31+32+33)-(3+6+9+…… +99)
= 17*33-3(1+2+3+…… +33)
= 17*33-3*17*33
= -2*17*33
= -1122