Given:
The system of equations is
...(i)
...(ii)
To find:
The number that must be multiplied with the second equation to eliminate the y-variable.
Solution:
Coefficient of y variable in equation (i) is 3 and in equation (ii) is -1.
To eliminate y-variable the absolute value of coefficients of y-variables should be same.
So, we need to multiply the second equation by 3 to eliminate the y-variable
Multiplying equation (ii) by 3, we get
...(iii)
Adding (i) and (iii), we get


Divide both sides by 7.

Put x=12 in (i).



Divide both sides by 10.

Therefore, x=12 and y=10.
Answer:
44
Step-by-step explanation:
I just used mental math soooo.......
have a great day luvs <3
1 km = 1000m
so 4 km = 4(1000) = 4000 m
so Kali runs 4000 m per day
4000/400 = 10 laps per day
for 3 days = 3(10) = 30 laps for 3 days