2x + y = 8
x - y = 10
--------------add
3x = 18
x = 6
x - y = 10
6 - y = 10
-y = 10 - 6
-y = 4
y = -4
solution is : (6,-4)
Answer:
c
Step-by-step explanation:
x+x=90
2x=90 ,x=45 ,∆BAD=45
Answer: Choice C.
and Choice E. 
Step-by-step explanation:
Algebraic exponents.
Answer:
4a^2 - 15b + 9b^2
Step by step explanation: