Please, use " ^ " to denote exponentiation: x^2 + 4x - 21 = 0
Factor: (x+7)(x-3)=0
Solve for the 2 roots: x= -7 and x= 3: {3, -7} Note how this is in set notation.
A triangle is 180 so 180-110=70 and 70 divided by 2 is 35 so the other two angles are 35 degrees
This would look like 6x/11. Since the problem doesn’t state the answer then you would simply write the expression.
E - 30. From 6 to 9 is increase of 1.5times
So if one bit of the length, is half the size of the other bit then we can make the following equation, for x being the length of rope:
x + 2x = 66
3x = 66
x = 22
That is the length, of the smaller one (half the big one), so 2x = 44. Hence d) is your answer.
Hope I helped!