Answer:
a =
Step-by-step explanation:
Given
ai + bj and 5i - 2j are perpendicular and b = 3, that is
ai + 3j and 5i - 2j are perpendicular, then
The scalar product = 0 , that is
5a - 6 = 0 ( add 6 to both sides )
5a = 6 ( divide both sides by 5 )
a =
45/5 = 9minutes/wall = 1wall/9minute/4 people = (1/36) per minute per person
(1/36)*6 = 1/6 wall per minute per 6 people * 24 = 4 walls in 24 minutes
24 Minutes total
Answer:
x = 48/7
Step-by-step explanation:
There's two good ways to do this problem.
Option 1:
Translate "x varies directly as y" into the equation y=kx
Then you have to find k. After you "reset" your y=kx equation, fill in k and then solve for x. See image.
Option 2:
Translate "varies directly" into a proportion, which is two fractions equal to each other:
x/y = x/y
Fill in the three numbers given and cross multiply and solve to find the fourth number. See image.