Photo math helps it worked for me so might help you :)
Answer:
a) Similar triangles are triangles with the same shape but not necessarily the same size
b) 15/45 = 8/x
1/3 = 8/x (simplify the 15/45)
x = 8 * 3 (cross multiplication)
x = 24
c) y^2 = 15^2 + 8^2 (Pythagoras theorem)
y = *square root of* 15^2 + 8^2
y = 17
1/3 = 17/z
z = 17 * 3 (cross multiplication)
z = 51
Yes, it is. You may prove it using something like this: 1 is an integer. 1-1 is a difference between integers. A difference between integers returns an integer, so 0 is an integer.
( 2a + 3 ) - ( 4a - 8 ) = 7
2a + 3 - 4a + 8 = 7
-2a + 11 = 7
-2a = -4
a = -4 / -2
a = 2
