In an examination 70% passed economics and 65% passed history, each student passed at least one of the two subjects 1) what percentage of students passed in both subjects

2) if the number of students in the class is 80 how many passed in both subjects

step-by-step explanation:

i hate black

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

a and c

step-by-step explanation: