A. 2/5 B. 1/3 just like the other person said lol
-- 30 miles per hour
-- $6.50 per hour
-- 365 days per year
-- 60 seconds per minute
-- $2.49 per pound
-- 3.47⁹ per gallon
-- 1800 calories per day
-- 360 degrees per revolution
Answer:
the answer is 24
Step-by-step explanation:
applyourknowledge
Answer:
70 students
Step-by-step explanation:
As, 30% Mike surveyed
And these 30% are 21 students
So 30% of X = 21
= 30/100 x X = 21
= 30X = 2100
So X = 2100/30
X = 70
So 70 students were surveyed
Given:
The system of equations:


To find:
The number that can be multiplied by the second equation to eliminate the x-variable when the equations are added together.
Solution:
We have,
...(i)
...(ii)
The coefficient of x in (i) and (ii) are 1 and
respectively.
To eliminate the variable x by adding the equations, we need the coefficients of x as the additive inverse of each other, i.e, a and -a So, a+(-a)=0.
It means, we have to convert
into -1. It is possible if we multiply the equation (ii) by -5.
On multiplying equation (ii) by -5, we get
...(iii)
On adding (i) and (iii), we get

Here, x is eliminated.
Therefore, the number -5 can be multiplied by the second equation to eliminate the x-variable.