Answer:
whos ur math teacher
Step-by-step explanation:
He would have drank 22.4 litres of water in 14 days
I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:
<span>-2x-9y=-25
-4x-9y=-23
you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -
Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.
Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest
Good luck!</span>
Answer:
2 or -2
Step-by-step explanation:
If x² - 8x = -12
Step 1
We find x by solving
x² - 8x = -12
We equate to zero
x² - 8x + 12 = 0
We factorise
x² - 6x - 2x + 12 = 0
x(x - 6) -2(x - 6) = 0
(x - 6) (x - 2) = 0
x - 6 = 0, x = 6
x - 2 = 0, x = 2
x = 6 or 2
Step 2
What is x - 4?
When x = 6
= 6 - 4 = 2
When x = 2
= 2 - 4 = -2
Therefore, x - 4 = 2 or -2
Answer:
x = 15
Therefore, the length and width are 31 and 47.
Step-by-step explanation:
Perimeter = (2x + 1) + (2x + 1) + (3x + 2) + (3x + 2) = 156
Simplified,
10x + 6 = 156
Subtract 6 from both sides, then divide by 10.
10x = 150
x = 15
To find the length and width, substitute 15 (the value of x) into the individual equations.
2(15) + 1 = 31
3(15) + 2 = 47
