<span>f(5)= 2+5 = 7
</span><span>g(5)= 5^2+5 = 25 +5 = 30
</span><span>(f - g) (-5) = 7 - 30 = -23
answer is </span><span>D.-23</span>
y = x + 2
Step-by-step explanation:
General formula for any straight line:
y = mx + c
Where
m = gradient
c = constant
m = y2 - y1/x2 - x1
m = (4 - ( -2))/(2 - ( -4))
m = 6/6
m = 1
y = (1)x + c
y = x + c
Substitute any coordinate from the line of the equation.
4 = 2 + c
c = 2
substitute m and c into general formula
y = mx + c
y = x + 2
Let t, f, and s be the amount of 25%, 40%, and 60% solutions used.
We are told s=3f. The general equation is:
100(0.25t+0.4f+0.6s)/(t+s+f)=45, and using s=3f we have:
(0.25t+0.4f+1.8f)/(t+4f)=0.45
(0.25t+2.2f)/(t+4f)=0.45
0.25t+2.2f=0.45t+1.8f
0.25t+0.4f=0.45t
0.4f=0.2t
t=2f, remembering that s=3f, will allow us to solve for f
t+s+f=60, using t and s from above
2f+3f+f=60
6f=60
f=10 L then
s=3f=30 L and t=2f=20L
So 20L of 25%, 10L of 40%, and 30L of 60% acid solutions need to be mixed to make 60L of 45% acid solution.
Answer:
2/3
Step-by-step explanation:
Look at what you are getting on the right hand question. 10a +10b has a common factor that can be pulled out. It is 10
10a + 10b = 10(a + b)
Now look at the denominator
9x - 9y = 9(x -y)
There are a lot of possible answers.
Mine would be to multiply 3/5 * 10/9
so
(10a + 10b)/(9x - 9y) = 2/3
