Show all your steps to your answer. 9x +6y = 78
3х - 6y = -30

x=4

Step-by-step explanation:

You put 9x+6y=78 over 3x-6y=-30. Then, you are going to add the two equations. So, you are going to do 9x+3x, 6y-6y (since the second 6 is negative, it ends up subtracting), and 78-30. You will end up canceling the 6y's, and end up with 12x=48. Then, you will divide 48 by 12, and get x=4. Hope this helped:)

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²

it has to have an angle of 90 degrees