Answer:
∑j=15(5j−12)
Step-by-step explanation:
For j = 1 up to j = 5
j = 1
(5j - 12) = (5(1) - 12) = 5 - 12 = - 7
j = 2
(5j - 12) = (5(2) - 12) = 10 - 12 = - 2
j = 3
(5j - 12) = (5(3) - 12) = 15 - 12 = 3
j = 4
(5j - 12) = (5(4) - 12) = 20 - 12 = 8
j = 5
(5j - 12) = (5(5) - 12) = 25 - 12 = 13
(-7 + (-2) + 3 + 8 + 13)
42/2=21 (is the sum of both lengths)
2x+11=21
2x=10
x=5
length= 16
width=5
Answer:
65
Step-by-step explanation:
5^2=25
3x25= 75
75- (2x5)
65
Answer:
228.65
Step-by-step explanation:
0.17 times 1345
Answer:
Step-by-step explanation:
Given is a system of equations as
We have 5 variables and 3 equations
a) coefficient matrix of this system is
1 -4 0 -1 0\\
0 1 0 -2 0\\
0 0 0 1 2\\
We find that x3 has no coefficient in any of the equations so we can omit x3 and write as equations for 4 variables as
1 -4 -1 0\\
0 1 -2 0\\
0 0 1 2\\
b) Augmented matrix is
1 -4 -1 0\\ 7
0 1 -2 0\\
3
0 0 1 2\\3
c) For row operations to ehelon form
we can do R1+4R2 = R1
We get
1 0 -9 0 \\ 19
0 1 -2 0 \\ 3
0 0 1 2 \\ 3
Now let us do R1 = R1+9R3 and R2 = R2+2R3
1 0 0 0 \\ 46
0 1 0 0 \\ 9
0 0 1 2 \\ 3
d) We find that there are infinite solutions to the system in parametric form, since x4 and x5 are linked with only one equation
e) x1 = 46, x2 = 9, x4+2x5 =3
Or x1 =46, x2 =9, x4 = 3-2x5, x5 = x5 is the parametric solution