236.5% is the correct answer
Answer:
Step-by-step explanation:
4.5x=90
x=20 history
28 chemistry
42 math
They add to 90.
History test=x
Chemistry test=1.4x
Math test=(1.5)(1.4)=2.1x
They add to 90
Answer:100 chocolates
Step-by-step explanation:
20 chocolate in each box so 20 time 5 is 100 so 20 time 11 is 220
Answer:
<em>Thus, the dimensions of the metal plate are 10 dm and 8 dm.</em>
Step-by-step explanation:
For a quadratic equation:

The sum of the roots is -b and the product is c. Note the leading coefficient is 1.
We know the perimeter of the rectangular metal plate is 36 dm and its area is 80 dm^2. Being L and W its dimensions, then:
P=2(L+W)=36
A=L.W=80
Note both formulas are closely related to the roots of the quadratic equation, we only need to adjust the data for the perimeter to be exactly the sum of L+W and not double of it.
Thus we use the semi perimeter instead as P/2=L+W=18
The quadratic equation is, then:

Factoring by finding two numbers that add up to 18 and have a product of 80:

The solutions to the equation are:
x=10, x=8
Thus, the dimensions of the metal plate are 10 dm and 8 dm.
1) Answer: 21
As y varies directly with x, this means that the ratio y/x is always a constant.
In other words, the equation can be written as y = kx, where k is a constant term.
Thus,

y = 21
2) Answer: C
Exactly the same process as above.
Here's another method:
25 = k(140)
k = 25/140 = 5/28
Thus, when y = 36, 36 = kx
36 = 5/28(x)
36 * 28/5 = x; x = 201.6
3) 9 = k(12)
9/12 = k and k = 3/4
4) On the graph, it hits y = 1 at x = 4.
Thus, we can rewrite the equation as:
y = (1/4)x, where the constant term is 1/4
5) y = kx
The distance represents the x-ordinates, and the time represents the y-ordinates.
9.5/475 = 0.02
4 = 0.02(x), in hours.
x = 200 miles.