1/40 in 30 mins = 2/40 in 1 hour
2/40= 0.05 miles per hour
2x+4y=0
3x+y=10
So what we want to do is get y onto one side by itself using whatever equation you like.
So I'm taking 2x+4y=0 and subtracting 4y from both sides
So we end up with
2x=4y
Divide both sides by four
2/4x is 1/2 x
So we get 1/2x=y
Take this and plug it into the other equation
3x+y=10
3x+1/2x=10
Add your like terms
3 1/2x=10
Putting 3 1/2 as a mixed number we get 7/2
So..
7/2x=10
Multiply by the opposite of 7/2 on both sides
Which is 2/7 this will cancel out the left side.
So we end up with
X= 10•2/7
X=20/7
Which is 2 and 6/7 as a mixed number.
f(x)=2x^3+2x^2-4x
The zeros of polynomial functions
2x^3 + 2x^2 - 4x = 0
2x(x^2 + x - 2) = 0
2x(x - 1)(x + 2) = 0
2x = 0; x = 0
x - 1 = 0; x = 1
x + 2 = 0; x = -2
Answer
x = -2 , 0 , 1