An ordered pair (x,y) is a solution to a system of equations if it makes all the equations true.
Let's check whether (–1, 5) makes the equations true.
Plugging –1 in the first equation for x and 5 in for y, we get
–1 + 5 = 4: TRUE
Plugging –1 in the second equation for x and 5 in for y, we get
–1 – 5 = –6: TRUE
Since it makes both the equations true, it's a solution to the system of equations. So the answer choice is D, the 4th one.
Answer:
So try 0-6
Step-by-step explanation:
Answer:
1.5
Step-by-step explanation:
its 1.5 not 1/5
Answer:
16,242. 7 cm^3.
Step-by-step explanation:
We need to cut off a square piece at the 4 corners of the cardboard.
Let the length of their edges be x cm.
The volume of the box will be:
V = height * width * length
V = x(100-2x)(40-2x)
V = x(4000 - 200x - 80x + 4x^2)
V = x(4x^2 - 280x + 4000)
V = 4x^3 + - 280x^2 + 4000x
Finding the derivative:
dV / dx = 12x^2 - 560x + 4000 = 0 ( when V is a maxm or minm.)
4(3x^2 - 140x + 1000) = 0
x = 37.86, 8.80.
Looks like x = 8.80 is the right value but we can check this out be looking at the sign of the second derivative:
V" = 24x - 560, when x = 8.8 V" is negative so this is a Maximum for V.
So the maximum volume of the box is when x = 8.8 so we have
V = 8.8(100-2(8.8)(40 - 2(8.8)
= 16,242. 7 cm^3.
Answer:
40
Step-by-step explanation:
-3 2
-15 - 2 = -17
1 5
-1 - 25 = -26
5<em> </em> -1
-25 - (-1) = - 24
1 <em> -5</em>
2 - <em>15</em> = -13
<em>-3</em> 2
area = |-17 - 26 - 24 - 13|/2 = |-80|/2 = 80/2 = 40
Answer: 40
