Answer:
-8
Step-by-step explanation:
5(x+12)= 20
5x+60= 20
5x= -40
x= -8
Answer:
x=5, y=2
Step-by-step explanation:
You simply write down what you see:
3x - 4y + 4x - 5y = 17
2x - 3y + 3x - 5y = 9
Then you simplify by grouping the x and the y terms:
7x - 9y = 17
5x - 8y = 9
Now you want to get equal amounts of x or y. Let's go for x. If we multiply the top eq with 5 and the bottom one with -7, we get:
35x - 45y = 85
-35x + 56y = -63
-------------------------+ now we can add them:
11y = 22 divide by -11
y = 2
So 7x - 18 = 17, x =5
Finally, it makes sense to double check by filling in these answers in the original equations, just to see if no mistakes were made:
3*5 - 4*2 = 7
4*5 - 5*2 = 10
7+10 = 17: ok!
2*5 - 3*2 = 4
3*5 - 5*2 = 5
4+5 = 9: ok!
I would estimate it as (300 x 7) = 2100
Then I would subtract (11 x 7) + 77 from that to get the exact answer of 2023
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I didn't use a calculator or paper. The 'trick' is to notice that 289 = (300 - 11)
Answer:
The mean is 19.5
Step-by-step explanation:
You have to add all of the numbers up then divide by how many numbers there are.
Ex: 5, 5, 6, 7
add them up and you get 23
Divide 23 by how many numbers you have, which in this case, is 4
The answer to this example would be 5.75
Answer:
1.275
Step-by-step explanation:
