Answer:
A and B are correct
Step-by-step explanation:
if x:y is 1:3 then x is 1 and y is 3
1/3 of 3 is 1 so A is correct
3/4(1+3) is 3 so B is correct
But
1/4 × 3 is not 1 so C is not correct
3/4 ×1 is not 3 so D isn't correct
Answer:
D
Step-by-step explanation:
The letter D includes a curved line, unlike the letters X, M, and F.
6x - 17 = 7 ........ added 1x to both sides
6x = 24 ............. added 17 to both sides
x = 4 ................. divided by 6 on both sides
so x=4
First notice that the triangle with sides

and the triangle with sides

are similar. This is true because the angle between sides

in the smaller triangle is clearly

, while the angle between sides

in the larger triangle is clearly

. So the triangles are similar with sides

corresponding to

, respectively.
Now both triangles are

, which means there's a convenient ratio between its sides. If the length of the shortest leg is

, then the length of the longer leg is

and the hypotenuse has length

.
Since

is the shortest leg in the larger triangle, it follows that

, so
X = 21 + 34
Answer: x = 55°