We can use linear combinations of the equations to eliminate variables.
3x - 4y = 1
-2x + 3y = 1
To eliminate y we'll make the linear combination of 3 times the first equation minus four times the second.
9x - 12y = 3
-8x + 12y = 4
Adding,
x = 7
We could solve for y directly but let's use another linear combination, twice the first plus three times the second:
2(3x - 4y) + 3(-2x + 3y)= 2(1)+3(1)
y = 5
Check: 3(7)-4(5)=1 good. -2(7)+3(5)=1 good.
Q18 Answer: (7,5)
y = -3x + 5
5x - 4y = -3
4y +1(5x - 4y) = 4(-3x + 5) + 1(-3)
5x = -12x + 20 -3
17 x = 17
x = 1
y = -3(1) + 5 = 2
Check: 5(1) - 4(2) = -3 good
Q19 Answer (1,2)
6x + 5y = 25
x = 2y + 24
6x = 12y + 144
5y = 25 - 12y - 144
17y = -119
y = -119/17= -7
x = 2y+24= 10
Check: 6(10)+5(-7)=25 good 2y+24=2(-7)+24=10=x good
Q20 Answer (10,-7)
3x + y = 18
-7x + 3y = -10
9x + 3y = 54
9x - -7x = 54 - -10
16x = 64
x=4
y = 18 -3x = 18-12=6
Check: 3(4)+6=18 good, -7(4)+3(6)=-10 good
Q21 Answer: (4,6)
Before you start working on this problem, make sure you know
how to use a couple of the tools in your toolbox:
Tool #1: 37-1/2 percent means 0.375
Tool #2: In math problems, "of" almost always means "times".
====================================
Your question says
"37-1/2 percent of blank is 36".
Translate it with your tools:
0.375 times blank = 36 .
Divide each side by 0.375: Blank = 36 / 0.375 .
Now grab your pencil or your calculator, and find the value of that
fraction (do the division). Blank is equal to the value of the fraction.
To check your answer (find out whether it's correct):
Do exactly what the question says.
Multiply (0.375) times (your answer). If you get 36,
then your answer is correct. If not, it's not.
Answer:
It is 1) True hope this helps
Ummm we are allll gonna be dead cause Biden be da president
Answer:
350 lightbulbs
Step-by-step explanation:
First find the number of batches made.
20,000 divided by 400 = 50
This means that there are 50 batches in which 7 light bulbs will be selected at random to be inspected.
We can multiply the number of batches to the lightbulbs being inspected.
50 times 7 = 350
Therefore, 350 lightbulbs will be inspected.
Please tell me if I am incorrect :)