Answer:
The mean is 20
Step-by-step explanation:
17+19+21+23=80
80 div 4 = 20
First, expand the terms inside the bracket you will get
<span>[2(3+5)-2(4+1)]5
=</span><span>[2(8)-2(5)]5
=</span><span>[16-10]5
=6*5
=30</span>
180 + 30x = 60 + 50x
⇒ 20x = 120
⇒ x = 6 minutes
<span>it will take 6 minutes for Millie to catch up with Ben</span>
To solve, we will follow the steps below:
3x+y=11 --------------------------(1)
5x-y=21 ------------------------------(2)
since y have the same coefficient, we can eliminate it directly by adding equation (1) and (2)
adding equation (1) and (2) will result;
8x =32
divide both-side of the equation by 8
x = 4
We move on to eliminate x and then solve for y
To eliminate x, we have to make sure the coefficient of the two equations are the same.
We can achieve this by multiplying through equation (1) by 5 and equation (2) by 3
The result will be;
15x + 5y = 55 ----------------------------(3)
15x - 3y =63 --------------------------------(4)
subtract equation (4) from equation(3)
8y = -8
divide both-side of the equation by 8
y = -1
