Answer:
The students spent 135 minutes in lecture and 115 minutes in a lab.
Step-by-step explanation:
Let x and y be the respective amount of time students spent in lecture and lab.
x-20=y --- eqn 1
x+y=250 --- eqn 2
From eqn 1, x=y+20 --- eqn 3
Sub eqn 3 into eqn 2:
y+20+y=250
2y=230
y=115
Sub y=115 into eqn 3:
x=115+20
=135
∴x=135, y=115
Answer:
Length=10 Inches
Width=10 Inches
Step-by-step explanation:
Volume of the box 
Height=8 Inches
Base Perimeter =40 Inches
Volume of a box=lbh
SInce h=8 in, V=800.
Then:
8bl=800
bl=100
Base Perimeter=40 Inches
Perimeter of the Base= 2(l+b)
Therefore: 2(l+b)=40
Substituting
Recall:
Therefore:
Length=10 Inches
Width=10 Inches
Answer:110
Step-by-step explanation:
its right i know
Answer:
The ordered pair is (2,3)
Step-by-step explanation:
we know that
If a system of equations has infinite solutions, then the equations are the same
we have
3ax+3y=5b -----> equation A
2x+y=5 ----> equation B
Multiply equation B by 3 both sides
3*(2x+y)=5*3
6x+3y=15 -----> equation C
Compare equation A and equation C
so
3ax=6x------> 3a=6 -----> a=2
5b=15 ------> b=3
The ordered pair is (2,3)
Answer:
Number of $5 bills = 32
Number of $10 bills = 14
Number of $20 bills = 8
Step-by-step explanation:
Let x number of $5, y number of $10 and z number of $20
The number of $5 bills exceeds twice the number of $10 bills by 4.
Therefore, x = 2y + 4
The number of $20 bills is 6 fewer than the number of $10 bills.
Therefore, z = y - 6
A wallet contains $460 in $5, $10, and $20 bills.
Therefore,
5x + 10y + 20z = 460
Substitute x and y into equation
5(2y+4) + 10y + 20(y-6) = 460
10y + 20 + 10y + 20y - 120 = 460
40y - 100 = 460
40y = 460 + 100
40y = 560
y = 14
- Put the value of y into x = 2y + 4 and solve for x
x = 2(14) + 4
x = 32
- Put the value of y into z = y - 6 and solve for z
z = 14 - 6
z = 8
Hence, the each type of bills,
Number of $5 bills = 32
Number of $10 bills = 14
Number of $20 bills = 8
