For the following system, if you isolated x in the second equation to use the substitution method, what expression would you substitute into the first equation?
3x + y = 8
−x − 2y = −10
a.) −2y + 10
b.) 2y + 10
c.) 2y − 10
d.) −2y − 10

Assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.