First, let's put the second equation, <span>x-2.23y+10.34=0, in terms of y:
x - 2.23y +10.34 = 0
2.23y = x + 10.34
y = .45x + 4.64
Now we can substitute the right side of this equation for y in the first equation
</span><span>y=2x^2+8x
.45x + 4.64 = 2x^2 + 8x
Turn it into a quadratic by getting 0 on one side:
2x^2 + 8x - .45x - 4.64 = 0
2x^2 + 7.55x - 4.64 = 0 Divide both sides by 2
x^2 + 3.76x - 2.32 = 0
x =( -b +/- </span>√(b² - 4ac) ) / 2a
x =( -3.76 +/- √(14.14 + 9.28)) ÷ 2
x = .54 or -4.31
Plug the x values into y = .45x + 4.64
y = .45 (.54) + 4.64
y = 4.88 when x= .54
y = .45 (-4.31) + 4.64
y = 2.70 when x= -4.31
Solution set:
{ (0.54, 4.88) , (-4.31, 2.70) }
Answer: There are 15 friends.
Step-by-step explanation:
We know that there is N friends (N is the number that we are looking for)
Each friend weights 1/20 ton.
Now, the weight of the N friends together is N times 1/20 ton.
Then we have:
N*(1/20) ton = 3/4 ton
We solve this for N.
First multiply both sides by 20.
20*N*(1/20) = N = 20*(3/4) = 60/4 = 15
Answer about 25
Step-by-step explanation:
Answer:
no
Step-by-step explanation:
A circle will fail the vertical line test, which means a vertical lines intersects two or more points. If it fails the vertical line test, it is not a function