area of a triangle = 1/2 base x height
56.4 = 1/2 x 12 x height
56.4 = 6 x height
height = 56.4 /6 = 9.4cm
You subtract negative 4 and negative 12...think in a number line and you find negative 4 and then you decrease( which means you move to your left of the number line) and find negative 12 and then you count the spaces you took to get to negative 12
There's two ways, you can either multiply 11 and 7 to get 77 and then divide by 2, OR, you can divide 11 by 2 and get 5.5 and multiply that by 7, hope this makes sense, if you don't understand just comment and I'll explain it more :)
Answer:
No solutions
Explanation:
The given system of equations is
2y = x + 9
3x - 6y = -15
To solve the system, we first need to solve the first equation for x, so
2y = x + 9
2y - 9 = x + 9 - 9
2y - 9 = x
Then, replace x = 2y - 9 on the second equation
3x - 6y = -15
3(2y - 9) - 6y = -15
3(2y) + 3(-9) - 6y = -15
6y - 27 - 6y = -15
-27 = -15
Since -27 is not equal to -15, we get that this system of equation doesn't have solutions.
Answer:
Step-by-step explanation:
B. -3
Hope that helps!