-3x+2y=7 -3x-2y=4 I need to combine this to I don’t know how

You have to combine like terms.

-3x+2y=7    

+

-3x-2y=4

=

-6x=11

Step-by-step explanation:

-3x+(-3x)=-6x

2y+(-2y)=0

7+4=11

i belive those are the ones that are under 90 degreese.

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560