Answer:
C. 40-4x-12x^2
Step-by-step explanation:
very simple
? – (20 – 4x – 5x2) = 20 – 7x2, so ? = 20 – 7x2 + (20 – 4x – 5x2)
? = 20 – 7x2 + (20 – 4x – 5x2)=20-7x²+20-4x-5x²=40-12x²-4x
Answer:
756 m²
Step-by-step explanation:
I just know the answer XD
Answer:
third option
Step-by-step explanation:
We just have to calculate 2x² - 4x - (x² + 6x). 2x² - x² = x² and -4x - 6x = -10x so the answer is x² - 10x.
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!
