During the vietnam war, north vietnam sent troops and supplies to south vietnam

To supply the Vietcong's troops/followers.

Explanation: North Vietnam sent supplies like troops, ammunition etc. to South Vietnam through Laos and Cambodia to supply their troops and followers during the Vietnam War.

he is known for discovering   the fossil of a female hominin australopithecine   known as "lucy" in the afar triangle region of hadar, ethiopia.

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simplify brackets

8 - 2a - 7 = a + 40

simplify 8 - 2a - 7 to -2a + 1

-2a + 1 = a + 40

add 2a to both sides

1 = a + 40 + 2a

simplify a + 40 + 2a to 3a + 40

1 = 3a + 40

subtract 40 from both sides

1 - 40 = 3a

simplify 1 - 40 o -39

-39 = 3a

divide both sides by 3

-39/3 = a

simplify 39/3 to 13

-13 = a

switch sides

a = -13