They are all eawualateral
U just gotta do it you know
3a + 6b = 45
2a - 2b = -12....multiply by 3
----------------
3a + 6b = 45
6a - 6b = - 36 ...(result of multiplying by 3)
---------------add
9a = 9
a = 1
3a + 6b = 45
3(1) + 6b = 45
3 + 6b = 45
6b = 45 - 3
6b = 42
b = 7
solution is : (1,7)
-8+b2-(5+b2). Since the - is outside the paranthesis the signs inside change: -8+b2-5-b2. -8-5=-3, b2-b2=0. Your answer: -3 :)