Answer:
130x+150y=1,920
Step-by-step explanation:
Why that is the equation is he learned 130 words per month in Portugal and 150 words per month in Brazil. Added together it is 1,920.
So the equation is 130x+150y=1,920.
Multiply each payout by the corresponding probability and take the total:
E[X] = 0×0.5 + 5×0.2 + 8×0.15 + 10×0.1 + 15×0.05 = 3.95
You solve an equation like this by adding the opposite of the constant to both sides of the equation.
... V -16 +16 = -32 +16 . . . . . addition property of equality: if a=c, then a+b = c+b
... V + 0 = -16 . . . . . . . . . . . . additive inverse property of integers: -16+16 = 0
... V = -16 . . . . . . . . . . . . . . . identity element of addition: V+0 = V
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<em>You can always do the same thing to both sides of an equation.</em> Here, it is useful to add the opposite of -16 to both sides. That way the constant on the left becomes zero, so you only have the variable by itself—which is what you want.
62 is 50% of 124 (62*2=124)