Let's plug in (18,10) into each answer choice until we find the one that has it as a solution.
A) 2x - y = 26
2(18) - 10 = 26
36 - 10 = 26
26 = 26
Your answer is A.
I'll just do the rest to show that you the they are incorrect.
B) x + y = 18
18 + 10 = 18
28 ≠ 18
C) 2x - 2y = 36
2(18) - 2(10) = 36
36 - 20 = 36
16 ≠ 36
D) x - y = -28
18 - 10 = -28
8 ≠ -28
Your answer is A) 2x - y = 26.
Answer: option d. the argument is valid by the law of detachment.
The law of detachment consists in make a conlcusion in this way:
Premise 1) a => b
Premise 2) a is true
Conclusion: Then, b is true
Note: the order of the premises 1 and 2 does not modifiy the argument.
IN this case:
Premise 1) angle > 90 => obtuse
Premise 2) angle = 102 [i.e. it is true that angle > 90]]
Conclusion: it is true that angle is obtuse
Answer:
A=1, B=3, C=15
Step-by-step explanation:
I think that
1(3x+3)=15
3x+3=15
3x=12
x=4