How many world wars have there been

there  have been 2  world wars

Explanation:

1.World War I (28 July 1914 to 11 November 1918)

2. World War II (1939 to 1945)

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

hi   i took this test in k12 2 weeks ago your answer is the name of it 14 points it failed because america was not behind him with this idea and it nevr passed the sentate

2   irelenad and jews wernt with him because he was focusing more on the war then them